fix: Add missing attestations permission for build provenance

Fixed GitHub Actions error "Resource not accessible by integration" by adding
the required attestations: write permission to build_and_publish_docker.yml.

The attest-build-provenance action requires three specific permissions:
- id-token: write (for OIDC token minting)
- contents: read (for repository access)
- attestations: write (for persisting build attestations)

This resolves the integration permission error that was preventing Docker
image attestation generation during the build process.

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/build_and_publish_docker.yml

@@ -17,6 +17,7 @@ jobs:
       contents: read
       packages: write
       id-token: write
+      attestations: write
 
     steps:
     - name: Checkout repository