Use type hinting generics in standard collections (#19046)

aka PEP 585, added in Python 3.9

 - https://peps.python.org/pep-0585/
 - https://docs.astral.sh/ruff/rules/non-pep585-annotation/

tests/rest/client/test_sync.py

@@ -20,7 +20,6 @@
 #
 import json
 import logging
-from typing import List
 
 from parameterized import parameterized
 
@@ -131,7 +130,7 @@ class SyncFilterTestCase(unittest.HomeserverTestCase):
         self.assertEqual(len(events), 1, [event["content"] for event in events])
         self.assertEqual(events[0]["content"]["body"], "with wrong label", events[0])
 
-    def _test_sync_filter_labels(self, sync_filter: str) -> List[JsonDict]:
+    def _test_sync_filter_labels(self, sync_filter: str) -> list[JsonDict]:
         user_id = self.register_user("kermit", "test")
         tok = self.login("kermit", "test")