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/key/v2/test_remote_key_resource.py

@@ -19,7 +19,7 @@
 #
 #
 from io import BytesIO, StringIO
-from typing import Any, Dict, Optional, Union
+from typing import Any, Optional, Union
 from unittest.mock import Mock
 
 import signedjson.key
@@ -156,7 +156,7 @@ class EndToEndPerspectivesTests(BaseRemoteKeyResourceTestCase):
     endpoint, to check that the two implementations are compatible.
     """
 
-    def default_config(self) -> Dict[str, Any]:
+    def default_config(self) -> dict[str, Any]:
         config = super().default_config()
 
         # replace the signing key with our own