ci: Add Dependabot to keep GitHub actions up to date

[jamacku]

Dependabot will help you to keep you notified about new releases and help you update your workflows.

Interval is set to monthly so it won't make too much noise.

Original content

Differential ShellCheck is a GitHub action that performs differential ShellCheck scans on shell scripts changed via PR and reports results directly in PR.

I saw that your scripts are in great shape, but I think that you might find differential-shellcheck action useful. It is able to produce reports in SARIF format. GitHub understands this format and is able to display it nicely as a PR comment, and on the Files Changed tab, please see below.

Documentation is available at @redhat-plumbers-in-action/differential-shellcheck. Let me know If you are missing some feature or setting. I'm always happy to extend functionality.

Note: I have also added Dependabot to keep your workflows up to date

/cc @zdohnal

[jamacku]

Oh, never mind, I just noticed that you already have a shellcheck that uses SARIF. And since you don't have any shellcheck warnings in your current code base, you probably don't need differential scans. But I think you still might be interested in Dependabot.