bpo-37642: Update acceptable offsets in timezone (GH-14878) (#15226)

bpo-37642: Update acceptable offsets in timezone (GH-14878) (#15226)

This fixes an inconsistency between the Python and C implementations of
the datetime module. The pure python version of the code was not
accepting offsets greater than 23:59 but less than 24:00. This is an
accidental legacy of the original implementation, which was put in place
before tzinfo allowed sub-minute time zone offsets.

GH-14878

(cherry picked from commit 92c7e30adf5c81a54d6e5e555a6bdfaa60157a0d)