build(deps): bump actions/attest-build-provenance from 2 to 3

Bumps [actions/attest-build-provenance](https://github.com/actions/attest-build-provenance) from 2 to 3.
- [Release notes](https://github.com/actions/attest-build-provenance/releases)
- [Changelog](https://github.com/actions/attest-build-provenance/blob/main/RELEASE.md)
- [Commits](actions/attest-build-provenance@v2...v3)

---
updated-dependencies:
- dependency-name: actions/attest-build-provenance
  dependency-version: '3'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/dockgen.yml

@@ -46,7 +46,7 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
 
       - name: Generate artifact attestation
-        uses: actions/attest-build-provenance@v2
+        uses: actions/attest-build-provenance@v3
         with:
           subject-name: ghcr.io/${{ github.repository }}
           subject-digest: ${{ steps.push.outputs.digest }}