[ModelicaSystem] fix usage of ModelicaSystemCmd

Author: syntron

OMPython/ModelicaSystem.py

@@ -1197,7 +1197,7 @@ def _parse_om_version(version: str) -> tuple[int, int, int]:
 
     def _process_override_data(
             self,
-            om_cmd: ModelicaSystemCmd,
+            om_cmd: ModelExecutionCmd,
             override_file: OMCPath,
             override_var: dict[str, str],
             override_sim: dict[str, str],