gh-128341: Use _Py_ABI_SLOT in stdlib modules (#145770) Rename from _Py_INTERNAL_ABI_SLOT to _Py_ABI_SLOT and define the macro using _PyABIInfo_DEFAULT. Use the ABI slot in stdlib extension modules to enable running a check of ABI version compatibility. _tkinter, _tracemalloc and readline don't use the slots, hence they need explicit handling. Co-authored-by: Victor Stinner <vstinner@python.org>