Also use UTC in xfel-calibrate with no --request-time specified

src/xfel_calibrate/calibrate.py

@@ -610,7 +610,7 @@ def run(argv=None):
 
     # request_time is in local timezone
     if args["request_time"] == "Now":
-        request_time = datetime.now()
+        request_time = datetime.now(tz=timezone.utc)
     else:
         request_time = datetime.fromisoformat(args["request_time"])