Heuristics for Dependabot config file validation

[marcrohlfs]

I noticed that there are additional checks called "Dependabot config file validation" in open pull requests. Interesting enough, these checks are (often?) not in pull requests where the .github/dependabot.yml is changed, but they appear in pull requests where it is not changed. Cannot prove the behaviour by 100%, I'm still observing. That's why I decided for a discussion instead of a bug report for now.

Has anybody noticed similar behavior? Or am I misinterpreting the purpose of this check?