Update publish_release action to commit and push PrintVersion.swift changes if needed

[TTOzzi]

Related to #834

We had hoped that the version print issue would be fixed in the Swift 6.1 release, but unfortunately, it seems that it hasn’t been addressed.

As I understand it, swift-toolchain references swift-format by a specific branch(https://github.com/swiftlang/swift/blob/release/6.1/utils/update_checkout/update-checkout-config.json#L211), so the current behavior of the publish_release action — where the change to PrintVersion.swift is included only in a tag and not pushed to a branch — means that the update doesn’t make it into the distributed toolchain 🤔

This PR updates the publish_release action so that when PrintVersion.swift is updated, the change is committed and pushed to the branch as well.

It seems like another possible approach could be to have update-checkout-config in Swift point to a tag of swift-format instead of a branch — but I’m not sure which option would be better.

[bnbarham]

Unfortunately this is unlikely to have the intended effect, since publish_release is going to run around (and possibly after) the toolchain release. It's clear we need to do something here though 🤔

[TTOzzi]

Unfortunately this is unlikely to have the intended effect, since publish_release is going to run around (and possibly after) the toolchain release. It's clear we need to do something here though 🤔

Oh, I see — so publish_release runs after the toolchain release…
We do run a prerelease using the same workflow before the official release, but since it uses a different version name (e.g. 601.0.0-prerelease-2025-03-28), that probably won’t help here.
Looks like we’ll need to explore a different approach 🤔