Change site packages look up to use sysconfig instead of distutils

[DanielNoord]

Steps

• Write a good description on what the PR does.

Description

While is was reading up on distutils etc I thought I would try and see if we can remove all calls to it.

There are three calls to distutils, which should all be done in separate PRs because of the complexity and risk of errors. If you agree I think we should try and put them in 2.9.1 as well (I know, another delay) so we can combine all fixes to the YOLO-option and removal of distutils at the same time. (YOLO-option from #1321, that is.)

For the change in this PR:
get_python_lib returns the directory of site-packages. "Return the directory for either the general or platform-dependent library installation. If plat_specific is true, the platform-dependent include directory is returned; if false or omitted, the platform-independent directory is returned."
This functionality is "replaced" by sysconfig.get_path. By using both purelib and platlib we got both of them again.

Type of Changes

	Type
✓	🔨 Refactoring

Related Issue

[cdce8p]

I haven't looked at it yet. Just one comment about the timeline. I would suggest / prefer to put this into 2.10. Yeah it's awesome that we'll remove the distutils dependency, but it isn't that urgent. Better to do one step at a time. That would also make debugging any issues much easier.

[DanielNoord]

I haven't looked at it yet. Just one comment about the timeline. I would suggest / prefer to put this into 2.10. Yeah it's awesome that we'll remove the distutils dependency, but it isn't that urgent. Better to do one step at a time. That would also make debugging any issues much easier.

Okay! I have added it as the milestone to all PRs.

[Pierre-Sassoulas]

We could also create a 2.9.2 release, there's almost 50 issues in 2.9.1, it's a lot for astroid. (Especially since the fix to symlinks is a much awaited bug fix). I released 2.9.1, I'll let you judge if 2.9.2 is necessary.

[Pierre-Sassoulas]

🎉 Small step toward removing distutils, great !

[cdce8p]

Looks good! Thanks @DanielNoord!
I'll review the others too, but we could start with merging this one.