[3.13] gh-119724: Revert "bpo-45759: Better error messages for non-matching 'elif'/'else' statements (GH-29513)" (GH-119974) (GH-120013)

This reverts commit 1c8f912ebdfdb146cd7dd2d7a3a67d2c5045ddb0.
(cherry picked from commit 31a4fb3c74a0284436343858803b54471e2dc9c7)