https://pip.pypa.io/en/stable/news/ 21.3.1 (2021-10-22)

• In-tree builds are now the default. --use-feature=in-tree-build is now ignored.

https://distlib.readthedocs.io/en/stable/overview.html#id1

• fix for Python 3.10

Related updates (https://repology.org/projects/?inrepo=sagemath_develop&outdated=True):

• certifi
• pyzmq: Fix build errors; zeromq, pyzmq: Update; setuptools: upgrade to 59.2.0 #32828: setuptools
• tox
• virtualenv
• flit_core: Update to 3.4.0; setuptools_scm: Update to 6.3.2 #32707: flit-core 3.4.0, setuptools-scm

Depends on #32751

CC: @orlitzky

Component: packages: standard

Author: Matthias Koeppe

Branch/Commit: 760ff09

Reviewer: Michael Orlitzky

Issue created by migration from https://trac.sagemath.org/ticket/32671