Update python3 to 3.9.6

[mkoeppe]

https://docs.python.org/release/3.9.6/whatsnew/changelog.html#python-3-9-6-final

CC: @dimpase

Component: packages: standard

Author: Matthias Koeppe

Branch/Commit: 223bfa1

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/32104

[mkoeppe]

Branch: u/mkoeppe/update_python3_to_3_9_6

[mkoeppe]

Reviewer: https://github.com/mkoeppe/sage/actions/runs/1161483651

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Commit: 223bfa1

[mkoeppe]

New commits:

223bfa1

build/pkgs/python3: Update to 3.9.6

[mkoeppe]

comment:4

The tests look all fine, needs review

[mkoeppe]

Changed reviewer from https://github.com/mkoeppe/sage/actions/runs/1161483651 to https://github.com/mkoeppe/sage/actions/runs/1161483651, ...

[dimpase]

comment:5

GH tests all seem to fail (for unlrelated reasons, I guess)

[mkoeppe]

comment:6

Replying to @dimpase:

GH tests all seem to fail (for unlrelated reasons, I guess)

No they don't - where did you look?

[dimpase]

comment:7

OK, it's fine. Looked at wrong place, sorry.

[dimpase]

Changed reviewer from https://github.com/mkoeppe/sage/actions/runs/1161483651, ... to Dima Pasechnik

[vbraun]

Changed branch from u/mkoeppe/update_python3_to_3_9_6 to 223bfa1