bpo-43916: Apply Py_TPFLAGS_DISALLOW_INSTANTIATION to selected types (GH-25748)

Apply Py_TPFLAGS_DISALLOW_INSTANTIATION to the following types:

* _dbm.dbm
* _gdbm.gdbm
* _multibytecodec.MultibyteCodec
* _sre..SRE_Scanner
* _thread._localdummy
* _thread.lock
* _winapi.Overlapped
* array.arrayiterator
* functools.KeyWrapper
* functools._lru_list_elem
* pyexpat.xmlparser
* re.Match
* re.Pattern
* unicodedata.UCD
* zlib.Compress
* zlib.Decompress
diff --git a/Modules/cjkcodecs/multibytecodec.c b/Modules/cjkcodecs/multibytecodec.c
index 5070c98..cb7182f 100644
--- a/Modules/cjkcodecs/multibytecodec.c
+++ b/Modules/cjkcodecs/multibytecodec.c
@@ -748,7 +748,8 @@ static PyType_Slot multibytecodec_slots[] = {
 static PyType_Spec multibytecodec_spec = {
     .name = MODULE_NAME ".MultibyteCodec",
     .basicsize = sizeof(MultibyteCodecObject),
-    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+              Py_TPFLAGS_DISALLOW_INSTANTIATION),
     .slots = multibytecodec_slots,
 };