gh-99051: remove duplicated test from test_weakref (GH-99052)

(cherry picked from commit 8463cb5)

Co-authored-by: Nikita Sobolev <[email protected]>

Author: miss-islington

Lib/test/test_weakref.py

@@ -597,7 +597,7 @@ class C(object):
         # deallocation of c2.
         del c2
 
-    def test_callback_in_cycle_1(self):
+    def test_callback_in_cycle(self):
         import gc
 
         class J(object):
@@ -637,40 +637,11 @@ def acallback(self, ignore):
         del I, J, II
         gc.collect()
 
-    def test_callback_in_cycle_2(self):
+    def test_callback_reachable_one_way(self):
         import gc
 
-        # This is just like test_callback_in_cycle_1, except that II is an
-        # old-style class.  The symptom is different then:  an instance of an
-        # old-style class looks in its own __dict__ first.  'J' happens to
-        # get cleared from I.__dict__ before 'wr', and 'J' was never in II's
-        # __dict__, so the attribute isn't found.  The difference is that
-        # the old-style II doesn't have a NULL __mro__ (it doesn't have any
-        # __mro__), so no segfault occurs.  Instead it got:
-        #    test_callback_in_cycle_2 (__main__.ReferencesTestCase) ...
-        #    Exception exceptions.AttributeError:
-        #   "II instance has no attribute 'J'" in <bound method II.acallback
-        #       of <?.II instance at 0x00B9B4B8>> ignored
-
-        class J(object):
-            pass
-
-        class II:
-            def acallback(self, ignore):
-                self.J
-
-        I = II()
-        I.J = J
-        I.wr = weakref.ref(J, I.acallback)
-
-        del I, J, II
-        gc.collect()
-
-    def test_callback_in_cycle_3(self):
-        import gc
-
-        # This one broke the first patch that fixed the last two.  In this
-        # case, the objects reachable from the callback aren't also reachable
+        # This one broke the first patch that fixed the previous test. In this case,
+        # the objects reachable from the callback aren't also reachable
         # from the object (c1) *triggering* the callback:  you can get to
         # c1 from c2, but not vice-versa.  The result was that c2's __dict__
         # got tp_clear'ed by the time the c2.cb callback got invoked.
@@ -690,10 +661,10 @@ def cb(self, ignore):
         del c1, c2
         gc.collect()
 
-    def test_callback_in_cycle_4(self):
+    def test_callback_different_classes(self):
         import gc
 
-        # Like test_callback_in_cycle_3, except c2 and c1 have different
+        # Like test_callback_reachable_one_way, except c2 and c1 have different
         # classes.  c2's class (C) isn't reachable from c1 then, so protecting
         # objects reachable from the dying object (c1) isn't enough to stop
         # c2's class (C) from getting tp_clear'ed before c2.cb is invoked.