Refactor .github/workflows/check-locks-on-owners-submission.yml to use Submission module

[mgoerens]

The recently added submission module aims at factoring code and logic that is re-used at different place in different workflow.

In check-locks-on-owners-submission.yml, the logic for pulling modified files and perform check if only an OWNERS file is pushed is already implemented in the sumbission module.

[mgoerens]

closed as implemented in #454