Delete promote-build.yml in release branches

[epananth]

• This issue is blocking
• This issue is causing unreasonable pain

In our Arcade setup, we exclusively utilize main branch for promoting builds. Therefore, the promote-build.yml file should not be present in any of the release branches.

[riarenas]

@epananth, The changes to the release branches broke arcade-validation official in the publishing validation

[riarenas]

Maybe we just delete publishing validation in all non-main branches?

[epananth]

Merged. Closing this one