python3: bump version to 3.9.5

python3: bump version to 3.9.5

Refreshed Python patches.
Updated pip & setuptools version.

For pip, patch '001-pep517-pyc-fix.patch' was reworked.

Also, the current version of the bundled pip (21.1.1) no longer supports
Python2, so the 'py2.py3' suffix gets replaced with just py3.

For setuptools, there is no longer a script/module:
  https://github.com/pypa/setuptools/pull/2544

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>
(cherry picked from commit e312275dd9c25c4032b4d2d3623b042905c8bf16)