chore(ci): drop unused attestations permission

attestations: write is declared but nothing in the workflow uses
actions/attest-build-provenance — least-privilege says remove it.
Add it back with a scoped step if/when SLSA provenance is wired in.

Author: SoulKyu

.github/workflows/pulumi-release.yml

@@ -17,7 +17,6 @@ on:
 permissions:
   contents: write
   id-token: write
-  attestations: write
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}