Issue #18408: Fix typo in build_node_tree() of the parser module

Type "o" format of Py_BuildValue() is invalid: it must be "O".
Issue #18408: Fix Python-ast.c: handle init_types() failure (ex: MemoryError)
Issue #18408: Fix PyErr_NormalizeException(), handle PyObject_IsSubclass() failure

PyObject_IsSubclass() can fail and raise a new exception!
Issue #18408: Fix locale.localeconv(), handle PyDict_SetItemString() failure
Issue #18408: Handle PyArena_AddPyObject() failure in ast.c

PyList_Append() (called by PyArena_AddPyObject()) can fail because of a
MemoryError for example.
Issue #18408: Mention changes in Misc/NEWS
Close #18469: Replace PyDict_GetItemString() with _PyDict_GetItemId() in structseq.c

_PyDict_GetItemId() is more efficient: it only builds the Unicode string once.
Identifiers (dictionary keys) are now created at Python initialization, and if
the creation failed, Python does exit with a fatal error.

Before, PyDict_GetItemString() failure was not handled: structseq_new() could
call PyObject_GC_NewVar() with a negative size, and structseq_dealloc() could
also crash.
Issue #17767: test_locale now works with unittest test discovery.
Original patch by Zachary Ware.
Issue #17767: test_locale now works with unittest test discovery.
Original patch by Zachary Ware.
Issue #18266: test_largefile now works with unittest test discovery and
supports running only selected tests.  Patch by Zachary Ware.
Issue #18266: test_largefile now works with unittest test discovery and
supports running only selected tests.  Patch by Zachary Ware.
Issue #18408: Fix structseq_reduce(), handle PyDict_SetItemString() failure
Issue #18408: Fix time.tzset(), detect exception when calling PyInit_timezone()
Issue #18408: Fix heapq.heappop(), handle PyList_SetSlice() failure
Issue #18408: Fix ast_for_atom(), PyErr_Fetch(&type, &value, &tback) can set value to NULL
Issue #18408: Fix _PyImport_LoadDynamicModule(), handle PyUnicode_FromFormat() failure
Issue #18408: Fix PyErr_SetImportError(), handle PyDict_SetItemString() failure
Issue #18408: Fix listpop(), handle list_ass_slice() failure
Issue #18408: Fix Py_ReprEnter(), handle PyList_Append() failure
Issue #18408: Fix PyType_Ready(), handle _PyDict_SetItemId() failure