chore(deps): pin actions/attest-build-provenance action to e8998f9

Author: radagastbot[bot]

.github/workflows/cd.yaml

@@ -93,7 +93,7 @@ jobs:
           shasum -a 512 blog-${{ env.RELEASE_VERSION }}.tar.gz > blog-${{ env.RELEASE_VERSION }}.tar.gz.sha512
 
       - name: 📝 Attest release provenance
-        uses: actions/attest-build-provenance@v2
+        uses: actions/attest-build-provenance@e8998f949152b193b063cb0ec769d69d929409be # v2
         with:
           subject-path: "${{ github.workspace }}/blog-${{ env.RELEASE_VERSION }}.tar.gz"