[ModelicaSystem] fix pylint message

OMPython/ModelicaSystem.py:1787:16: W0612: Unused variable 'key' (unused-variable)

=> replace items() by values()

Author: syntron

OMPython/ModelicaSystem.py

@@ -1797,7 +1797,7 @@ def linearize(
         om_cmd.arg_set(key="overrideFile", val=override_file.as_posix())
 
         if self._inputs:
-            for key, data in self._inputs.items():
+            for data in self._inputs.values():
                 if data is not None:
                     for value in data:
                         if value[0] < float(self._simulate_options["startTime"]):