gh-100238: Vendor distutils for peg_generator

[lysnikolaou]

This puts all of distutils (except for the tests) under Tools and uses that both in the c-analyzer and the peg-generator. Stripping all the unnecessary parts of distutils should be done after b1 is released.

• Issue: PEP 632: Remove the distutils package (Python 3.12) #92584

• Issue: Update test_peg_generator to not need distutils & reenable it #100238

[ned-deily]

Is there a reason we can't use setuptools via pip install rather than bringing back all this code we just removed?

[lysnikolaou]

Not really. I opened this in a hurry to give @Yhg1s the option to unskip test_peg_generator before beta1, since the associated issue was marked as a release blocker. Since the consensus is that it's not, I'll take the time to port this to setuptools instead.