feat(ci): add attestations permission for build provenance (#119)

Enable SLSA build provenance attestation by granting the
attestations:write permission required by the shared
job-docker-build-push workflow.

Ref: platform-mesh/backlog#229


On-behalf-of: @SAP <bastian.echterhoelter@sap.com>

Signed-off-by: Bastian Echterhölter <bastian.echterhoelter@sap.com>

Author: nexus49

.github/workflows/pipeline.yml

@@ -15,6 +15,7 @@ permissions:
   issues: write
   packages: write
   pull-requests: write
+  attestations: write
 
 concurrency:
   group: ${{ github.ref }}