build(deps): bump actions/attest-build-provenance from 1.4.3 to 2.1.0

Bumps [actions/attest-build-provenance](https://github.com/actions/attest-build-provenance) from 1.4.3 to 2.1.0.
- [Release notes](https://github.com/actions/attest-build-provenance/releases)
- [Changelog](https://github.com/actions/attest-build-provenance/blob/main/RELEASE.md)
- [Commits](https://github.com/actions/attest-build-provenance/compare/1c608d11d69870c2092266b3f9a6f3abbf17002c...7668571508540a607bdfd90a87a560489fe372eb

)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/artifacts.yaml

@@ -178,14 +178,14 @@ jobs:
 
       # TODO: uncomment when the action is working for non ghcr.io pushes. GH Issue: https://github.com/actions/attest-build-provenance/issues/80
       # - name: Generate build provenance attestation
-      #   uses: actions/attest-build-provenance@1c608d11d69870c2092266b3f9a6f3abbf17002c # v1.4.3
+      #   uses: actions/attest-build-provenance@7668571508540a607bdfd90a87a560489fe372eb # v2.1.0
       #   with:
       #     subject-name: dexidp/dex
       #     subject-digest: ${{ steps.build.outputs.digest }}
       #     push-to-registry: true
 
       - name: Generate build provenance attestation
-        uses: actions/attest-build-provenance@1c608d11d69870c2092266b3f9a6f3abbf17002c # v1.4.3
+        uses: actions/attest-build-provenance@7668571508540a607bdfd90a87a560489fe372eb # v2.1.0
         with:
           subject-name: ghcr.io/dexidp/dex
           subject-digest: ${{ steps.build.outputs.digest }}