bpo-43908: Make heap types converted during 3.10 alpha immutable (GH-26351) (GH-26766)

* Make functools types immutable

* Multibyte codec types are now immutable

* pyexpat.xmlparser is now immutable

* array.arrayiterator is now immutable

* _thread types are now immutable

* _csv types are now immutable

* _queue.SimpleQueue is now immutable

* mmap.mmap is now immutable

* unicodedata.UCD is now immutable

* sqlite3 types are now immutable

* _lsprof.Profiler is now immutable

* _overlapped.Overlapped is now immutable

* _operator types are now immutable

* winapi__overlapped.Overlapped is now immutable

* _lzma types are now immutable

* _bz2 types are now immutable

* _dbm.dbm and _gdbm.gdbm are now immutable
(cherry picked from commit 00710e6346fd2394aa020b2dfae170093effac98)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>
diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c
index 30fb7c9..1d9d4cd 100644
--- a/Modules/arraymodule.c
+++ b/Modules/arraymodule.c
@@ -2997,7 +2997,7 @@ static PyType_Spec arrayiter_spec = {
     .name = "array.arrayiterator",
     .basicsize = sizeof(arrayiterobject),
     .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
-              Py_TPFLAGS_DISALLOW_INSTANTIATION),
+              Py_TPFLAGS_DISALLOW_INSTANTIATION | Py_TPFLAGS_IMMUTABLETYPE),
     .slots = arrayiter_slots,
 };