do not rely on the runner.yaml symlink in the test

The symlink is not registered in pants. So far, this is the first
time something has tried to access that file. So, just use the actual
file instead of the symlink

contrib/runners/python_runner/tests/unit/test_output_schema.py

@@ -66,7 +66,7 @@ def setUpClass(cls):
         assert_submodules_are_checked_out()
 
     def test_adherence_to_output_schema(self):
-        config = self.loader(os.path.join(BASE_DIR, "../../runner.yaml"))
+        config = self.loader(os.path.join(BASE_DIR, "../../python_runner/runner.yaml"))
         runner = self._get_mock_runner_obj()
         runner.entry_point = PASCAL_ROW_ACTION_PATH
         runner.pre_run()