[protection rules] Don't require approval from a code owner

It happens many times that users have write access to a repo but they are not owners for a piece of code. With the current settings, their approval don't count to allow merging, which is confusing and frustrating.

This also doesn't play well with the new dependabot auto-merge workflow (there are other ways to fix this, but this seems the most sensible way given what was mentioned above).