build(deps): Bump actions/attest-build-provenance

Bumps the github-actions group with 1 update: [actions/attest-build-provenance](https://github.com/actions/attest-build-provenance).


Updates `actions/attest-build-provenance` from 1.4.4 to 2.0.0
- [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@ef24412...619dbb2)

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

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

.github/workflows/at_server.yaml

@@ -179,7 +179,7 @@ jobs:
         run: |
           echo "hashes=$(cat checksums.txt | base64 -w0)" >> "$GITHUB_OUTPUT"
       - if: ${{ matrix.dart-channel == 'stable' && startsWith(github.ref, 'refs/tags/') }}
-        uses: actions/attest-build-provenance@ef244123eb79f2f7a7e75d99086184180e6d0018 # v1.4.4
+        uses: actions/attest-build-provenance@619dbb2e03e0189af0c55118e7d3c5e129e99726 # v2.0.0
         with:
           subject-path: 'sboms/**'
 

.github/workflows/promote_canary.yaml

@@ -164,7 +164,7 @@ jobs:
         working-directory: sboms
         run: |
           echo "hashes=$(cat checksums.txt | base64 -w0)" >> "$GITHUB_OUTPUT"
-      - uses: actions/attest-build-provenance@ef244123eb79f2f7a7e75d99086184180e6d0018 # v1.4.4
+      - uses: actions/attest-build-provenance@619dbb2e03e0189af0c55118e7d3c5e129e99726 # v2.0.0
         with:
           subject-path: 'sboms/**'