WIP: Backport of: Use manylinux2010 for python 3.9+ #5303 onto v0.18.x

[hmaarrfk]

Description

#5303

Checklist

• Docstrings for all functions
• Gallery example in ./doc/examples (new features only)
• Benchmark in ./benchmarks, if your changes aren't covered by an
  existing benchmark
• Unit tests
• Clean style in the spirit of PEP8

For reviewers

• Check that the PR title is short, concise, and will make sense 1 year
  later.
• Check that new functions are imported in corresponding __init__.py.
• Check that new features, API changes, and deprecations are mentioned in
  doc/release/release_dev.rst.

[hmaarrfk]

Sorry, i would like to cleanup the syntax first. I'll post a reference to the builds on my repo.

[jni]

All good @hmaarrfk, just want to make sure you can move on with things and keep the momentum going. Perhaps mark the PR as draft until you think it's it's ready to be merged?

[hmaarrfk]

@jni
thanks for helping fix the mrmeeseeks bot so quickly. lets use this PR as a backport test.