Remove prevent-migration-deletion job from build-and-publish job's needs

[MattyTheHacker]

If it's determined that prevent-migration-deletion can run fine on pushes then this check can be added back and the if statement removed from the other job.

As it stands the build-and-publish job will never run on pushes to main

[CarrotManMatt]

Cheers for catching this!

The prevent-migration-deletion job should only be run on PRs so that database migrations can always be deleted manually by overriding and pushing straight to main without a PR. It would be nice to make the needs for the build-and-release job conditional, so that the PR docker images are not built if the prevent-migration-deletion job fails, but there is no requirement to rely upon it when a push occurs. However, it is my understanding that setting that up would be very complex & hacky. Therefore, this solution is fine.

It will result in:

• PR docker image containers will be built even if the prevent-migration-deletion job fails
• PRs will still not be able to be merged if the prevent-migration-deletion job fails due to it being a required
• The prevent-migration-deletion job will not be run for push events