Just the necessary bits to get it to work with Python 3.10.
Not updating to the latest version, for now at least, as that
requires building it with `poetry` (which we currently do not have).
* python3.8: bulk removal of now obsolete "_python38" packages.
Done via scripting. No functional change intended or expected.
Some manual tweaks will follow.
* python3.8: further manual tweaks after bulk-3.8-removal.
Unlike the previous commit with automated changes,
I've tested builds for *these* recipes in beta4 64 bits.
