WebHost: Update UTC datetime usage (timezone-naive) (#4906)

Utils.py

@@ -18,6 +18,8 @@ import logging
 import warnings
 
 from argparse import Namespace
+from datetime import datetime, timezone
+
 from settings import Settings, get_settings
 from time import sleep
 from typing import BinaryIO, Coroutine, Optional, Set, Dict, Any, Union, TypeGuard
@@ -1291,6 +1293,15 @@ def is_iterable_except_str(obj: object) -> TypeGuard[typing.Iterable[typing.Any]
     return isinstance(obj, typing.Iterable)
 
 
+def utcnow() -> datetime:
+    """
+    Implementation of Python's datetime.utcnow() function for use after deprecation.
+    Needed for timezone-naive UTC datetimes stored in databases with PonyORM (upstream).
+    https://ponyorm.org/ponyorm-list/2014-August/000113.html
+    """
+    return datetime.now(timezone.utc).replace(tzinfo=None)
+
+
 class DaemonThreadPoolExecutor(concurrent.futures.ThreadPoolExecutor):
     """
     ThreadPoolExecutor that uses daemonic threads that do not keep the program alive.