[test_ModelicaSystem] simplify test_customBuildDirectory

Author: syntron

tests/test_ModelicaSystem.py

@@ -131,14 +131,11 @@ def test_customBuildDirectory(tmp_path, model_firstorder):
 
 @skip_on_windows
 @skip_python_older_312
-def test_getSolutions_docker(model_firstorder_content):
+def test_getSolutions_docker(model_firstorder):
     omcp = OMPython.OMCProcessDocker(docker="openmodelica/openmodelica:v1.25.0-minimal")
     omc = OMPython.OMCSessionZMQ(omc_process=omcp)
 
-    modelpath = omc.omcpath_tempdir() / 'M.mo'
-    modelpath.write_text(model_firstorder_content)
-
-    file_path = pathlib.Path(modelpath)
+    file_path = model_firstorder.as_posix()
     mod = OMPython.ModelicaSystem(
         fileName=file_path,
         modelName="M",