test_compliance_check_aasx: Fix outdated test-case

Previously, the BaSyx-Python AASX reader returned
a "File not found" exception, when an AASX-file
could not be found. However, now it appears that
it returns `is not a valid ECMA376-2 (OPC) file`
instead.

We update the unittest to reflect this change.

test/test_compliance_check_aasx.py

@@ -20,7 +20,7 @@ def test_check_deserialization(self) -> None:
         compliance_tool.check_deserialization(file_path_1, manager)
         self.assertEqual(2, len(manager.steps))
         self.assertEqual(Status.FAILED, manager.steps[0].status)
-        self.assertIn("No such file or directory", manager.format_step(0, verbose_level=1))
+        self.assertIn("is not a valid ECMA376-2 (OPC) file", manager.format_step(0, verbose_level=1))
         self.assertEqual(Status.NOT_EXECUTED, manager.steps[1].status)
 
         # Todo add more tests for checking wrong aasx files