gh-110178: Use fewer weakrefs in test_typing.py (#110194)

Confirmed that without the C changes from #108517, this test still segfaults with only 10 weakrefs.

Author: JelleZijlstra

Lib/test/test_typing.py

@@ -550,7 +550,7 @@ def test_many_weakrefs(self):
             with self.subTest(cls=cls):
                 vals = weakref.WeakValueDictionary()
 
-                for x in range(100000):
+                for x in range(10):
                     vals[x] = cls(str(x))
                 del vals