Release 12.3.0 into trunk

[iangmaia]

Releasing new version 12.3.0.

What's Next

PR Author: Be sure to create and publish a GitHub Release pointing to trunk once this PR gets merged,
copy/pasting the following text as the GitHub Release's description:

### New Features

- `buildkite_pipeline_upload`: prepend `.buildkite/` to the `pipeline_file` parameter to enforce our conventions [#608]

### Bug Fixes

- `create_release-backmerge_pull_request`: Fix the pre-check logic verifying if a PR is really needed or if there's nothing to backmerge. [#607]

### Internal Changes

- `buildkite_pipeline_upload`: makes sure all values passed in the environment parameter are strings [#608]

[dangermattic]

	1 Warning
⚠️	PR is not assigned to a milestone.

Generated by 🚫 Danger

[AliSoftware]

I was pondering why this was a 12.3.0 and not a 12.2.1 given the only changes are either internal or bug fixes, not new features nor breaking changes…

That made me realize that the fact that the buildkite_pipeline_upload action have changed its behavior to now prepend .buildkite/ on relative paths of pipeline_file I think that change (from line 32) should be:

• Either under Bug Fixes, rather than Internal Changes
• Or under "New Features", which I think makes a bit more sense to me given the change
• Or one could even argue it's a breaking change in practice—as it changes the behavior and will require changes in any client repos that were already using that action with a relative path. But I think too few client repos have adopted that action before the change made in this release-toolkit propagated too far, and you know exactly which ones they are and are already planning to update them ASAP… so maybe that's not worth marking this as a breaking in that context…

In any case, I think we should move line 32 of the CHANGELOG in an upper section before landing this PR and doing the release 🙂

[iangmaia]

I was pondering why this was a 12.3.0 and not a 12.2.1 given the only changes are either internal or bug fixes, not new features nor breaking changes…

I've changed it manually to 12.3.0, related to what you pointed out below plus IMO it's a significant behavior change (though without affecting the API).

That made me realize that the fact that the buildkite_pipeline_upload action have changed its behavior to now prepend .buildkite/ on relative paths of pipeline_file I think that change (from line 32) should be:

• Either under Bug Fixes, rather than Internal Changes
• Or under "New Features", which I think makes a bit more sense to me given the change
• Or one could even argue it's a breaking change in practice—as it changes the behavior and will require changes in any client repos that were already using that action with a relative path. But I think too few client repos have adopted that action before the change made in this release-toolkit propagated too far, and you know exactly which ones they are and are already planning to update them ASAP… so maybe that's not worth marking this as a breaking in that context…

In any case, I think we should move line 32 of the CHANGELOG in an upper section before landing this PR and doing the release 🙂

Agreed!