fix(ci): normalize release target_commitish for bump-back PR base

[leecalcote]

Problem

When v0.21.19 was released, the Publish Node.js Package workflow's "Open PR with package.json version bump" step failed with:

fatal: refusing to fetch into branch 'refs/heads/master' checked out at '/home/runner/work/sistent/sistent'
##[error]The process '/usr/bin/git' failed with exit code 128

The step is continue-on-error: true, so the publish itself still succeeded — but the version-bump-back PR was never opened and master's package.json drifted from the version published to npm (it had to be opened manually as #1610).

Root cause

The step passed github.event.release.target_commitish straight into peter-evans/create-pull-request as base. That value can be either a bare branch name (master) or a fully-qualified ref (refs/heads/master), depending on how the release was created. create-pull-request's base must be a short branch name; given a full ref it tries to fetch into the currently checked-out branch, which git refuses (exit 128).

Fix

Resolve the target branch once in a new Resolve target branch step, stripping any refs/heads/ prefix, and reuse the normalized value for both the checkout ref and the bump-back PR base.

- name: "Resolve target branch"
  id: target_branch
  env:
    TARGET: ${{ github.event.release.target_commitish || 'master' }}
  run: echo "name=${TARGET#refs/heads/}" >> "$GITHUB_OUTPUT"

Testing

• python3 -c "import yaml; yaml.safe_load(...)" — workflow parses.
• The shell normalization is a standard ${VAR#prefix} strip: refs/heads/master → master, and a bare master is unchanged.
• End-to-end validation occurs on the next published release (the bump-back PR should open automatically instead of erroring).

[gemini-code-assist]

Note

Gemini is unable to generate a review for this pull request due to the file types involved not being currently supported.