gh-92049: Forbid pickling constants re._constants.SUCCESS etc (GH-92070)

Previously, pickling did not fail, but the result could not be unpickled.

Author: serhiy-storchaka

Lib/re/_constants.py

@@ -62,6 +62,8 @@ def __new__(cls, value, name):
     def __repr__(self):
         return self.name
 
+    __reduce__ = None
+
 MAXREPEAT = _NamedIntConstant(MAXREPEAT, 'MAXREPEAT')
 
 def _makecodes(*names):

Misc/NEWS.d/next/Library/2022-04-30-10-53-10.gh-issue-92049.5SEKoh.rst

@@ -0,0 +1,2 @@
+Forbid pickling constants ``re._constants.SUCCESS`` etc. Previously,
+pickling did not fail, but the result could not be unpickled.