Add python 3.10 support

[k-dominik]

Summary:

• dealt with deprecated Iterable import from collections

[hmeine]

The main change looks good to me. I cannot check the CI setup changes, but to me they also look like updates & cleanups that should be merged.

What about the failed checks? CMake failed with vigranumpy dependencies NOT found while TEST_VIGRANUMPY=1 – can that be related to these changes?

[hmeine]

Do the CI pipeline changes supercede #490? Would you suggest merging that as well / before this one?

[k-dominik]

Hey @hmeine,

thanks a lot for looking into this!! I'll poke around CI some more (I have avoided azure pipelines so far, so I still have to catch up there a bit). My current issue would be activating the right toolset for python 3.10 (so finding the right vcvarsall.bat or using the right parameters to get 14.2, and I'm not sure where to find it :D).

I'll try to get this running and will ping you again once this is worth looking at (and I formed an opinion on #490).

Cheers and have a great weekend!

[hmaarrfk]

I merged in the fixes in the code from this branch (trying to keep attribution).

I'm trying to fix the CIs in #514

[k-dominik]

thank you @hmaarrfk,

I'll close this PR then.