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/

contrib/graph/graph.py

@@ -24,7 +24,6 @@ import datetime
 import html
 import json
 import urllib.request
-from typing import List
 
 import pydot
 
@@ -33,7 +32,7 @@ def make_name(pdu_id: str, origin: str) -> str:
     return f"{pdu_id}@{origin}"
 
 
-def make_graph(pdus: List[dict], filename_prefix: str) -> None:
+def make_graph(pdus: list[dict], filename_prefix: str) -> None:
     """
     Generate a dot and SVG file for a graph of events in the room based on the
     topological ordering by querying a homeserver.
@@ -127,7 +126,7 @@ def make_graph(pdus: List[dict], filename_prefix: str) -> None:
     graph.write_svg("%s.svg" % filename_prefix, prog="dot")
 
 
-def get_pdus(host: str, room: str) -> List[dict]:
+def get_pdus(host: str, room: str) -> list[dict]:
     transaction = json.loads(
         urllib.request.urlopen(
             f"http://{host}/_matrix/federation/v1/context/{room}/"