Tweak dependency checking in doc/conf.py.

- Autogen most of the checked list.
- Replace outdated pydata_sphinx_theme entry.
- matplotlib and its dependency pillow don't need to be explicitly
  listed, as we already import matplotlib at the top of the file anyways
  so if it's not importable, we won't even reach _check_dependencies.

Author: anntzer

doc/conf.py

@@ -89,14 +89,11 @@
 
 def _check_dependencies():
     names = {
+        **{ext: ext.split(".")[0] for ext in extensions},
+        # Explicitly list deps that are not extensions, or whose PyPI package
+        # name does not match the (toplevel) module name.
         "colorspacious": 'colorspacious',
-        "IPython.sphinxext.ipython_console_highlighting": 'ipython',
-        "matplotlib": 'matplotlib',
-        "numpydoc": 'numpydoc',
-        "PIL.Image": 'pillow',
-        "pydata_sphinx_theme": 'pydata_sphinx_theme',
-        "sphinx_copybutton": 'sphinx_copybutton',
-        "sphinx_gallery": 'sphinx_gallery',
+        "mpl_sphinx_theme": 'mpl_sphinx_theme',
         "sphinxcontrib.inkscapeconverter": 'sphinxcontrib-svg2pdfconverter',
     }
     missing = []