The workflow was failing with:
```
The workflow is not valid. .github/workflows/docker-publish.yml (Line: 22, Col: 14): Unexpected symbol: '|'. Located at position 12 within expression: github.ref | replace('refs/tags/', '')
```
The `set-output` command is deprecated, so the issue has been fixed by utilising the `github.ref_name` context to retrieve the version tag that triggered the workflow.
> `github.ref_name`: The short ref name of the branch or tag that triggered the workflow run. This value matches the branch or tag name shown on GitHub. For example, `feature-branch-1`.
https://docs.github.com/en/actions/learn-github-actions/contexts
