Allow project restart

[lasantosr]

When upgrading shuttle version, a restart is required according to the docs:
https://docs.shuttle.rs/configuration/shuttle-versions#upgrading-shuttle-version

This PR allows the action to restart the project before the deployment

[jonaro00]

Thanks for the suggestion!

I think this is a good enough solution for those that want it, but restarting the project at each deployment can become very chaotic (especially if pushing commits rapidly), which is why we still recommend a manual restart when you want to upgrade the shuttle version.
I don't think having this as an official option is suitable, since we are planning to remove the need of restarting the project altogether (and each deployment gets its own up to date container).
So, I think we can leave this open for visibility, and let anyone who wants to use it do so.

P.S. You could also consider supporting the idle minutes flag.

[lasantosr]

I think this is a good enough solution for those that want it, but restarting the project at each deployment can become very chaotic (especially if pushing commits rapidly), which is why we still recommend a manual restart when you want to upgrade the shuttle version.

Having it as a variable allows the job to enable or disable it based on user input or other conditions.

If you're planning to remove the need of restarting the project, then I can understand why it's not being merged, thanks for the explanation!