Message 392502 - Python tracker

This is to update the bundled pip to 21.1.1.

Compared to 21.1, it includes a fix that suppresses a noisy message when distutils and sysconfig schemes do not match. 

I link this issue to 3.9 and 3.8 as well, as it could be nice to include it in the release for a better user experience, if we are not too close to the release deadline.