PYTHON-4449 Ensure resume options aren't combined during automatic retry (#1641)

Author: broadstack-au

pymongo/change_stream.py

@@ -179,8 +179,7 @@ def _change_stream_options(self) -> dict[str, Any]:
                 options["startAfter"] = resume_token
             else:
                 options["resumeAfter"] = resume_token
-
-        if self._start_at_operation_time is not None:
+        elif self._start_at_operation_time is not None:
             options["startAtOperationTime"] = self._start_at_operation_time
 
         if self._show_expanded_events: