[Tooling] Improve new_hotfix_release lane to work when there's no release tag

[iangmaia]

Related to AINFRA-1518

Description

This PR aims to add more robustness and require less manual intervention to the hotfix creation lane new_hotfix_release.

We have observed that sometimes it is possible that the release has been finalized but a release tag isn't present yet for some reason (likely due to the fact that the release hasn't been published yet), so release managers will get an error and require manual intervention.

This PR changes the code so that it, if not release tag is present, we start the hotfix branch based on the corresponding release branch.

Testing instructions

There are basically 3 test scenarios that can be simulated:

1. There is a release tag that can be used to create the hotfix branch
2. There's no tag, but there's still a release branch that can be used to create the hotfix branch
3. There's no tag or branch (error)

To test it, you can create test branches / tags (⚠️ delete them later or, even better, use this technique of pointing your working copy’s origin remote to a local bare repo instead ⚠️ ) and run bundle exec fastlane new_hotfix_release skip_confirm:false version_name:$VERSION build_code:$CODE and then answer no after the prompt so that the lane execution stops and check the printed values.

For example:

1. Create and push release branch release/30.6 (which doesn't exist and has no corresponding tag for that version)
2. Run bundle exec fastlane new_hotfix_release skip_confirm:false version_name:30.6 build_code:9999
3. It should use the release/30.6 branch instead of trying to use a tag. It should print:

Current release version: 26.3.1
New hotfix version: 30.6

Current build code: 1478
New build code: 9999

Branching from release/30.6

[mokagio]

Nitpick, and sort of out of scope because it would have required changing more of the existing code that this PR originally touched, but I noticed that other projects use hotfix_version as the name for this var, which to me sounds better in the context of this hotfix lane.

No big deal, it's just that the PR I looked before this used hotfix_version so this jumped to my attention, I think.

[iangmaia]

I think hotfix_version was an exception though, only DOApple (or maybe other one or two) used it, but admittedly I also like it 🙂 I'll update it in the PRs that are still open.

[iangmaia]

@AliSoftware I've implemented the last change we discussed about ensuring the hotfix branch doesn't exist on 56b313c .

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud