Description
Reintroduce the version setting, but only accepting the major.minor version (e.g. "3.10"). For a given Chaquopy version, the selection of available minor versions, and the micro version of each minor version, would still be limited to the ones we tested before release.
Do not set the default version from the buildPython, as that would make it inconsistent on different build machines. Instead, make buildPython default to the same as the runtime version, and make the runtime version default to the newest version which has a full set of packages in the pip repository. For Chaquopy 12.1 this will still be 3.8, as the other Python versions will only have whatever packages are necessary to run the tests.
At some point after release, we'll bring all the other versions as close as possible to parity with Python 3.8. The following Chaquopy version will then change the default Python version to 3.10, and from that point on, we'll probably only release new packages and versions for that.
If we ever do end up with different meta.yaml files for different Python versions, this can be handled using templating in meta.yaml, by implementing conda-build's template variables for environment variables including PY_VER. And If different Python versions require different patches, we can add conda-build's syntax for listing the patch files explicitly.