Documented Py_mod_multiple_interpreters default is incorrect

[encukou]

Docs added in #107306 say the default for Py_mod_multiple_interpreters is Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED, but the actual default is Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED (preserving pre-3.12 behaviour):

cpython/Objects/moduleobject.c

Lines 351 to 354 in 180ee43

	/* By default, multi-phase init modules are expected
	to work under multiple interpreters. */
	if (!has_multiple_interpreters_slot) {
	multiple_interpreters = Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED;

cc @ericsnowcurrently

Linked PRs

• gh-129405: Fix doc for Py_mod_multiple_interpreters default, and add test #129406