bpo-35336: Fix PYTHONCOERCECLOCALE=1 (GH-10806) (GH-10813)

Fix PYTHONCOERCECLOCALE=1 environment variable: only coerce the C
locale if the LC_CTYPE locale is "C".

(cherry picked from commit 55e498058faf8c97840556f6d791c2c392732dc3)
3 files changed