SKIP one more test which uses python for cross targets

Noticed another os test os__process_inherit_env which tries to
use a python file when run. Skip for cross.

TN: T616-039

Author: Aleksandra Pasek

testsuite/tests/os/process/inherit_env/test.yaml

@@ -1,2 +1,4 @@
 title: GNATCOLL.OS.Process test inherit_env parameter
 data: ["test_data/*.py"]
+control:
+  - [SKIP, "env.is_cross", "Test uses python which is not available on cross targets"]