[3.12] gh-127552: Remove comment questioning 4-digit restriction for ‘Y’ in datetime...

[3.12] gh-127552: Remove comment questioning 4-digit restriction for ‘Y’ in datetime.strptime patterns (GH-127590) (#127649)

gh-127552: Remove comment questioning 4-digit restriction for ‘Y’ in datetime.strptime patterns (GH-127590)

The code has required 4 digits for the year since its inclusion in the stdlib in 2002 (over 22 years ago as of this commit).
(cherry picked from commit 51cfa569e379f84b3418db0971a71b1ef575a42b)

Co-authored-by: Beomsoo Kim <beoms424@gmail.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>