gh-40049: Replace dead HTTP links in docs
    
I manually checked all links starting with "http://" and found
replacements for the dead ones. Huge shoutouts to the Internet Archive.

### 📝 Checklist

- [ ] I have created tests covering the changes.
- [x] I have updated the documentation and checked the documentation
preview.
    
URL: #40049
Reported by: Lennard Hofmann
Reviewer(s): Dima Pasechnik

Author: Release Manager

src/doc/de/thematische_anleitungen/sage_gymnasium.rst

@@ -1223,20 +1223,17 @@ Weiterführende Links und Literatur
 Das folgende Tutorial erklärt (auf englisch) wie Sage als einfacher Rechner benutzt werden kann. Hier
 finden sich auch viele Funktionen und Beispiele, welche für unsere Zwecke interessant sind.
 
-* http://www-rohan.sdsu.edu/~mosulliv/sagetutorial/sagecalc.html
+* https://mosullivan.sdsu.edu/sagetutorial/sagecalc.html
 
 Die offizielle deutsche Dokumentation von Sage ist noch im Aufbau und weit entfernt von einer
-vollständigen Dokumentation. Das Einführungstutorial ist jedoch auch auf deutsch verfügbar. Die offizielle
-Seite der deutschen Version von Sage findet sich hier:
-
-* http://www.sagemath.org/de/
+vollständigen Dokumentation. Das Einführungstutorial ist jedoch auch auf deutsch verfügbar.
 
 
 .. rubric:: Footnotes
 
-.. [#keywords] http://docs.python.org/2/reference/lexical_analysis.html#keywords
+.. [#keywords] https://docs.python.org/3/reference/lexical_analysis.html#keywords
 .. [#tutorial] http://doc.sagemath.org/html/de/tutorial/
 .. [#units] http://doc.sagemath.org/html/en/reference/calculus/sage/symbolic/units.html
 .. [#2dgraphics] http://doc.sagemath.org/html/en/reference/plotting/index.html
 .. [#scatterplot] http://doc.sagemath.org/html/en/reference/plotting/sage/plot/scatter_plot.html
-.. [#listcomp] http://docs.python.org/2/tutorial/datastructures.html#list-comprehensions
+.. [#listcomp] https://docs.python.org/3/tutorial/datastructures.html#list-comprehensions

src/doc/de/tutorial/programming.rst

@@ -435,8 +435,8 @@ Dictionaries
 Ein Dictionary (manchmal auch assoziativer Array genannt) ist eine
 Abbildung von 'hashbaren' Objekten (z.B. Strings, Zahlen und Tupel;
 Lesen Sie die Python documentation
-http://docs.python.org/tut/node7.html und
-http://docs.python.org/lib/typesmapping.html für weitere Details) zu
+http://docs.python.org/3/tutorial/datastructures.html und
+https://docs.python.org/3/library/stdtypes.html#typesmapping für weitere Details) zu
 beliebigen Objekten.
 
 ::

src/doc/en/constructions/algebraic_geometry.rst

@@ -331,7 +331,7 @@ Singular itself to help an understanding of how the wrapper works.
 
 -  Using Singular's ``BrillNoether`` command (for details see the section
    Brill-Noether in the Singular online documentation
-   (http://www.singular.uni-kl.de/Manual/html/sing_960.htm and the
+   (https://www.singular.uni-kl.de/Manual/4-3-0/sing_2254.htm and the
    paper {CF}):
 
    ::

src/doc/en/developer/coding_basics.rst

@@ -901,7 +901,7 @@ in particular, it is turned into ``\begin{gather} block
 ``align``) which in ordinary LaTeX would not be wrapped like this, you
 must add a **:nowrap:** flag to the MATH mode. See also `Sphinx's
 documentation for math blocks
-<http://sphinx-doc.org/latest/ext/math.html?highlight=nowrap#directive-math>`_. :
+<https://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html#directive-math>`_. :
 
 .. CODE-BLOCK:: rest
 

src/doc/en/faq/faq-contribute.rst

@@ -69,7 +69,7 @@ Another good place to take a look at is
 `Dive Into Python <https://diveintopython3.net>`_
 by Mark Pilgrim, which may be pretty helpful on some specific topics
 such as test-driven development. The book
-`Building Skills in Python <http://itmaybeahack.com/homepage/books/python.html>`_
+`Building Skills in Python <https://itmaybeahack.com/homepage/books/python.html>`_
 by Steven F. Lott is suitable for anyone who is already comfortable
 with programming.
 
@@ -129,9 +129,8 @@ resources can be found by a web search.
 * `pep8 <https://pypi.org/project/pep8>`_
 * `pydeps <https://pypi.org/project/pydeps>`_
 * `pycallgraph <https://pycallgraph.readthedocs.io>`_
-* `PyChecker <http://pychecker.sourceforge.net>`_
 * `PyFlakes <https://pypi.org/project/pyflakes>`_
-* `Pylint <https://www.logilab.org/project/pylint>`_
+* `Pylint <https://pylint.readthedocs.io>`_
 * `Python <https://www.python.org>`_ home page and the
   `Python standard documentation <https://docs.python.org>`_
 * `Snakefood <http://furius.ca/snakefood>`_
@@ -140,10 +139,10 @@ resources can be found by a web search.
 
 **Tutorials and books**
 
-* `Cython Tutorial <http://conference.scipy.org/proceedings/SciPy2009/paper_1/>`_
+* `Cython Tutorial <https://proceedings.scipy.org/articles/MJMV8092.pdf>`_
   by Stefan Behnel, Robert W. Bradshaw, and Dag Sverre Seljebotn
 * `Dive Into Python 3 <http://www.diveintopython3.net>`_ by Mark Pilgrim
-* `Fast Numerical Computations with Cython <http://conference.scipy.org/proceedings/SciPy2009/paper_2/>`_
+* `Fast Numerical Computations with Cython <https://proceedings.scipy.org/articles/GTCA8577.pdf>`_
   by Dag Sverre Seljebotn
 * `Official Python Tutorial <https://docs.python.org/3/tutorial/>`_
 

src/doc/en/faq/faq-general.rst

@@ -199,8 +199,6 @@ functionalities are made possible through FOSS projects such as
 * `OpenBLAS <https://www.openblas.net/>`_  --- an optimized BLAS library.
 * `Pari/GP <https://pari.math.u-bordeaux.fr>`_ --- a computer algebra
   system for fast computations in number theory.
-* `Pynac <http://pynac.sagemath.org>`_ --- a modified version of GiNaC
-  that replaces the dependency on CLN by Python.
 * `R <http://www.r-project.org>`_ --- a language and environment for
   statistical computing and graphics.
 * And many more too numerous to list here.

src/doc/en/faq/faq-usage.rst

@@ -219,8 +219,8 @@ by a web search.
 
 * `Building Skills in Python <http://homepage.mac.com/s_lott/books/python.html>`_
   by Steven F. Lott
-* `Dive into Python <http://www.diveintopython.net>`_ by Mark Pilgrim
-* `How to Think Like a Computer Scientist <http://www.openbookproject.net/thinkCSpy>`_
+* `Dive into Python <https://diveintopython3.net>`_ by Mark Pilgrim
+* `How to Think Like a Computer Scientist <https://www.openbookproject.net/thinkcs/python/english3e/>`_
   by Jeffrey Elkner, Allen B. Downey, and Chris Meyers
 * `Official Python Tutorial <https://docs.python.org/tutorial>`_
 * `Python <https://www.python.org>`_ home page and the
@@ -562,7 +562,7 @@ include the following:
     limit maxproc 512 2048
 
 then reboot. See
-`this page <http://www.macosxhints.com/article.php?story=20050709233920660>`_
+`this page <https://web.archive.org/web/20051106134912/http://www.macosxhints.com/article.php?story=20050709233920660>`_
 for more details.
 
 How do I plot the cube root (or other odd roots) for negative input?

src/doc/en/prep/Advanced-2DPlotting.rst

@@ -15,7 +15,7 @@ Attribution\-ShareAlike 3.0 license (`CC BY\-SA
 <http://creativecommons.org/licenses/by-sa/3.0/>`_).
 
 Thanks to Sage's integration of projects like `matplotlib
-<http://matplotlib.sourceforge.net/>`_, Sage has comprehensive
+<https://matplotlib.org/>`_, Sage has comprehensive
 two-dimensional plotting capabilities.  This worksheet consists of the
 following sections:
 

src/doc/en/prep/Quickstarts/NumAnalysis.rst

@@ -130,7 +130,7 @@ involved).
     425/32
 
 Now let's convert ``x`` to the IEEE 754 binary format that is commonly
-used in computers.  For `IEEE 754 <http://grouper.ieee.org/groups/754/>`_,
+used in computers.  For `IEEE 754 <https://en.wikipedia.org/wiki/IEEE_754>`_,
 the first step in getting the binary format is to normalize the number,
 or express the number as a number between 1 and 2 multiplied by a power of 2.
 For our ``x`` above, we multiply by `2^{-3}` to get a number between 1 and 2.