Revert "gh-46376: Return existing pointer when possible in ctypes (#1… (#108688)

This reverts commit 08447b5deb47e2a0df87fa0a0576d300e5c909b4.

Revert also _ctypes.c changes of the PyDict_ContainsString() change,
commit 67266266469fe0e817736227f39537182534c1a5.
3 files changed