feat(ci): add github app for git actions

[calvinbrewer]

Github actions that modify the main branch have issues with Github Rulesets:

remote: - Changes must be made through a pull request.        
remote: 
remote: - Commits must have verified signatures.        
remote:   Found 1 violation: 

This allows a Github app to bypass rulesets for Github actions.

[auxesis]

Makes sense, thanks @calvinbrewer.