Update Workflows to Version 0.18.4

[carpentries-bot]

🤖 This is an automated build

Update Workflows from sandpaper version 0.16.12 -> 0.18.4

• Auto-generated by create-pull-request on 2026-01-27T00:19+00:00

[github-actions]

ℹ️ Modified Workflows

This pull request contains modified workflow files and no preview will be created.

Workflow files modified:

• .github/workflows/README.md
• .github/workflows/docker_apply_cache.yaml
• .github/workflows/docker_build_deploy.yaml
• .github/workflows/docker_pr_receive.yaml
• .github/workflows/pr-comment.yaml
• .github/workflows/pr-preflight.yaml
• .github/workflows/sandpaper-version.txt
• .github/workflows/update-cache.yaml
• .github/workflows/update-workflows.yaml

If this is not from a trusted source, please inspect the changes for any malicious content.

[K-Meech]

@marcodallavecchia @uschille - are you happy for me to go ahead and merge this? There are some failing checks, but I messaged Robert Davey on slack (see my reply to his message in the #maintainers channel) and he said this is fine to ignore.

[marcodallavecchia]

Hey @K-Meech, I was also a bit confused by that error, but I don't have any issues with going ahead and merging this!

[uschille]

@K-Meech @marcodallavecchia I've gone ahead and merged the workflow update and applied the fixup described by @froggleston on Slack. As far as I can tell, the list of workflows/actions looks clean. Thank you all for looking into this.