Bump actions/attest-build-provenance from 2.3.0 to 2.4.0 (#697)

Bumps [actions/attest-build-provenance](https://github.com/actions/attest-build-provenance) from 2.3.0 to 2.4.0.
- [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@db473fd...e8998f9)

---
updated-dependencies:
- dependency-name: actions/attest-build-provenance
  dependency-version: 2.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/build-docker-images.yml

@@ -116,7 +116,7 @@ jobs:
             NODE_ARCH_RELEASE=${{ env.NODE_ARCH_RELEASE }}
             ${{ matrix.IMAGE.BUILD_ARGS }}
           push: ${{ (github.event_name == 'push' || github.event_name == 'schedule' || github.event_name == 'workflow_dispatch') && github.ref == 'refs/heads/main' }}
-      - uses: actions/attest-build-provenance@db473fddc028af60658334401dc6fa3ffd8669fd  # v2.3.0
+      - uses: actions/attest-build-provenance@e8998f949152b193b063cb0ec769d69d929409be  # v2.4.0
         with:
           subject-name: "ghcr.io/pyca/${{ steps.image-name.outputs.ATTEST_IMAGE }}"
           subject-digest: ${{ steps.docker-build.outputs.digest }}