Drop support for Python 3.9 (#590)

* Removed Python 3.9 and added 3.14 from tests

* Seems the world is not ready for 3.14 yet

Author: brownbaerchen

.github/workflows/ci_pipeline.yml

@@ -39,7 +39,7 @@ jobs:
       fail-fast: false
       matrix:
         env: ['base', 'fenics', 'mpi4py', 'petsc', 'pytorch']
-        python: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        python: ['3.10', '3.11', '3.12', '3.13']
     defaults:
       run:
         shell: bash -l {0}

README.md

@@ -35,7 +35,7 @@ implemented.
 -   Continuous integration via [GitHub
     Actions](https://github.com/Parallel-in-Time/pySDC/actions) and
     [Gitlab CI](https://gitlab.hzdr.de/r.speck/pysdc/-/pipelines) (through the [GitHub2Gitlab Action](https://github.com/jakob-fritz/github2lab_action))
--   Fully compatible with Python 3.9 - 3.12, runs at least on Ubuntu
+-   Fully compatible with Python 3.10 - 3.13, runs at least on Ubuntu
 
 ## Getting started