feat: allow dry runs

[armcknight]

Add an option to perform a dry run, which invokes craft prepare with the --dry-run option and creates the issue with dry-run label, which, if getsentry/publish#5819 is merged, would allow auto-approval of that issue and run craft publish also as a dry run.

Originating from the need here: getsentry/sentry-cocoa#5507; closes #42

[asottile-sentry]

I don't think you need to have publish or craft involved at all. just set up a thing which runs the dry run command locally

maybe set up some time to discuss this but I don't think we should build additional complexity into the already-complicated publish workflow to support this

[armcknight]

This is for an automated PR check run, so the suggestion to run something locally, manually, is a nonstarter.

[asottile-sentry]

I mean local to your repo -- you can run everything there

[BYK]

I'm also strongly opposed to this. You can run Craft in dry-run mode in your CI if this is concerning to you. And you can use its docker image if that makes your life easier.

If you can share your specific issue that you are trying to prevent (instead of just the solution you came up with) we might help you better @armcknight

[BYK]

@asottile-sentry I vote to close this PR and associated issue as won't fix.

[asottile-sentry]

yeah seems the correct action