Sort downloads table by version number, not release date

[hugovk]

• Sort the ["Looking for a specific release?"] table in reverse order by (major, manor, bugfix) release -- having the last 3.7 appear before the last 3.10 makes little sense. (Maybe split into multiple tables by (major, minor) to avoid having to scroll through 3.13.1-9 before you see 3.12?)

Originally posted by @gvanrossum in #2816 (comment)

https://www.python.org/downloads/

[hugovk]

Please see PR #2822.