gh-87634: remove locking from functools.cached_property (GH-101890)

Remove the undocumented locking capabilities of functools.cached_property.

Lib/test/test_functools.py

@@ -2931,21 +2931,6 @@ class OptionallyCachedCostItem:
     cached_cost = py_functools.cached_property(get_cost)
 
 
-class CachedCostItemWait:
-
-    def __init__(self, event):
-        self._cost = 1
-        self.lock = py_functools.RLock()
-        self.event = event
-
-    @py_functools.cached_property
-    def cost(self):
-        self.event.wait(1)
-        with self.lock:
-            self._cost += 1
-        return self._cost
-
-
 class CachedCostItemWithSlots:
     __slots__ = ('_cost')
 
@@ -2970,27 +2955,6 @@ class TestCachedProperty(unittest.TestCase):
         self.assertEqual(item.get_cost(), 4)
         self.assertEqual(item.cached_cost, 3)
 
-    @threading_helper.requires_working_threading()
-    def test_threaded(self):
-        go = threading.Event()
-        item = CachedCostItemWait(go)
-
-        num_threads = 3
-
-        orig_si = sys.getswitchinterval()
-        sys.setswitchinterval(1e-6)
-        try:
-            threads = [
-                threading.Thread(target=lambda: item.cost)
-                for k in range(num_threads)
-            ]
-            with threading_helper.start_threads(threads):
-                go.set()
-        finally:
-            sys.setswitchinterval(orig_si)
-
-        self.assertEqual(item.cost, 2)
-
     def test_object_with_slots(self):
         item = CachedCostItemWithSlots()
         with self.assertRaisesRegex(