apply branch protection rules

[plastikfan]

Require Pull Request(master)

• also ensure Do not allow bypassing the above settings is set
• change the ci workflow to trigger on pull requests only

[plastikfan]

With this rule in place, start using the Rebase and Merge option. This will ensure flat history

[plastikfan]

Also instead of using the endflow function (which for saftey reasons should either be renamed or deleted), we should now use an endfeat, which fetches from upstream.

stale local branches have to be deleted manually either using git fetch --prune or branch deletion with -D option