[3.13] gh-122571: Remove duplicate definition of PY_BUILTIN_HASHLIB_HASHES in configure.ac (GH-122572) (#122763)

gh-122571: Remove duplicate definition of PY_BUILTIN_HASHLIB_HASHES in configure.ac (GH-122572)

The redefinition in confdefs.h can cause issues with the
AX_CHECK_COMPILE_FLAG macro.
(cherry picked from commit b5e142ba7c2063efe9bb8065c3b0bad33e2a9afa)

Co-authored-by: Jonathan Protzenko <protz@microsoft.com>