Change master branch name on GitHub wordpress-develop security mirror to public-trunk

We are now running automated tests on coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. using the GitHubGitHub GitHub is a website that offers online implementation of git repositories that can can easily be shared, copied and modified by other developers. Public repositories are free to host, private repositories require a paid subscription. GitHub introduced the concept of the ‘pull request’ where code changes done in branches by contributors can be reviewed and discussed before being merged be the repository owner. Actions runner with the goal of transitioning off of Travis; however, we need to both reduce the runs because of usage limitations on private repos and also because it’s unnecessary to run all those tests on the same code content between mirrors all the time.

To that end, I am requesting that trunk (the master branch in the mirror) be synced to public-trunk on the GitHub wordpress-develop security mirror instead of master.

We are not close to moving off of Travis entirely yet but if this can be fit in sooner than later, that would be helpful so we can continue work on some related testing setups.