Adopt MSC4506 identifiers for the knock push rule

The knock push rules MSC has been published as MSC4506: rename the
experimental flag to msc4506_enabled, the rule id to
.org.matrix.msc4506.rule.knock and the condition kind to
org.matrix.msc4506.recipient_permission per its unstable prefix section.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Uk8aPxHn3BHCe52L226jdG

tests/push/test_bulk_push_rule_evaluator.py

@@ -653,7 +653,7 @@ class TestBulkPushRuleEvaluator(HomeserverTestCase):
 
 
 class TestKnockPushRules(HomeserverTestCase):
-    """Tests for the MSCxxxx knock push rule (`.org.matrix.mscxxxx.rule.knock`
+    """Tests for the MSC4506 knock push rule (`.org.matrix.msc4506.rule.knock`
     with the `recipient_permission` condition): a knock should notify exactly
     the members of the room whose power level lets them act on it.
     """
@@ -714,7 +714,7 @@ class TestKnockPushRules(HomeserverTestCase):
         )
 
     @override_config(
-        {"experimental_features": {"mscxxxx_knock_push_rule_enabled": True}}
+        {"experimental_features": {"msc4506_enabled": True}}
     )
     def test_knock_notifies_only_users_who_can_act(self) -> None:
         knock_event_id = self._knock_and_get_event_id()

tests/push/test_push_rule_evaluator.py

@@ -824,14 +824,14 @@ class PushRuleEvaluatorTestCase(unittest.TestCase):
 
     def test_recipient_permission(self) -> None:
         """
-        Test the MSCxxxx `recipient_permission` condition (knock push rules).
+        Test the MSC4506 `recipient_permission` condition (knock push rules).
         """
         evaluator = self._get_evaluator(
             {"membership": "knock"},
             action_power_levels={"invite": 50},
         )
         condition = {
-            "kind": "org.matrix.mscxxxx.recipient_permission",
+            "kind": "org.matrix.msc4506.recipient_permission",
             "key": "invite",
         }
 
@@ -854,7 +854,7 @@ class PushRuleEvaluatorTestCase(unittest.TestCase):
         # An action key with no known level never matches.
         self.assertFalse(
             evaluator.matches(
-                {"kind": "org.matrix.mscxxxx.recipient_permission", "key": "nonsense"},
+                {"kind": "org.matrix.msc4506.recipient_permission", "key": "nonsense"},
                 "@user:test",
                 None,
                 recipient_power_level=100,