ci(pr-build): use pr.head.sha as default ref

[piyoki]

Background

Currently, the version of artifact binaries in pr-build does NOT align with the latest head sha. This PR refactors the seed-build workflow and passes ref as inputs to the build process. In such a way, we may input ref precisely according to different scenarios.

Build (Main) uses ${{ github.ref }}

PR Build (Preview) uses ${{ github.event.pull_request.head.sha }}

Checklist

• The Pull Request has been fully tested
• There's an entry in the CHANGELOGS
• There is a user-facing docs PR against https://github.com/daeuniverse/dae

Full changelogs

• ci(pr-build): use pr.head.sha instead of github.sha
• ci(seed-build): add ref as input; default is github.ref
• ci(pr-build): use ref instead of sha as input
• ci(seed-build): add pr_build inputs to differentiate type
• fix: rework commit sha parser
• ci(seed-build): add pr_number input

Issue reference

NA

Test Result

https://github.com/daeuniverse/dae/actions/runs/5538510193/jobs/10108524157

[dae-prow]

🧪 Since the PR has been fully tested, please consider merging it.

[mzz2017]

LGTM. It's useful!