Avoid use of datetime.utc* methods deprecated in Python 3.12 (#93684)

Co-authored-by: Marc Mueller <30130371+cdce8p@users.noreply.github.com>

tests/components/google/conftest.py

@@ -20,6 +20,7 @@ from homeassistant.components.application_credentials import (
 from homeassistant.components.google import DOMAIN
 from homeassistant.core import HomeAssistant
 from homeassistant.setup import async_setup_component
+from homeassistant.util import dt as dt_util
 
 from tests.common import MockConfigEntry
 from tests.test_util.aiohttp import AiohttpClientMocker
@@ -138,9 +139,7 @@ def token_scopes() -> list[str]:
 def token_expiry() -> datetime.datetime:
     """Expiration time for credentials used in the test."""
     # OAuth library returns an offset-naive timestamp
-    return datetime.datetime.fromtimestamp(
-        datetime.datetime.utcnow().timestamp()
-    ) + datetime.timedelta(hours=1)
+    return dt_util.utcnow().replace(tzinfo=None) + datetime.timedelta(hours=1)
 
 
 @pytest.fixture