Set up test to confirm repository settings are as expected

[fevrin]

Background

We need to set up CI to check the repo's settings to confirm they're as expected or warn the user to change them. With gh installed, the following info can be used to determine the repository's settings:

• General repo settings
• Branch rules
• GitHub Actions perms
• Allowed GitHub Actions
• Branch protection

Some settings to check:

• Automatically delete head branches
• Always suggest updating pull request branches
• Require status checks to pass before merging
• Require branches to be up to date before merging
• Allow repository, and select non-repository, actions and reusable workflows
• Allow GitHub Actions to create and approve pull requests
• workflow permissions

Definition of Done

• GitHub Action set up to check for certain repository settings