Fix timezone issue for ingestion

[FlorianBracq]

When using pyhon >= 3.12, DeprecationWarning are visible with messages such as:

datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
self._ingest_client_resources_last_update = datetime.utcnow()

Fixed

Replace datetime.utcnow() with datetime.now(tz=dt.timezone.utc)