We haven't quite dropped Py3.8 support yet, so we can't use these workflows if
they're compiling with 3.11:
* upgrade-one-python-dependency (upgrading a single, targeted dep)
* compile-python-requirements (recompiling all deps without upgrading)
So, we "downgrade" those workflows to use 3.8, for now. We should revert this
commit when we drop 3.8 support.
Note: The upgrade-python-requirements.yml workflow is still using 3.8, so this
commit will update the other workflows to match that one.
a3bafb2ccd