fix(ci): grant write permissions to release workflow

The `actions/create-release@v1` action requires `contents: write`
permissions to create a GitHub release. The workflow was failing
because these permissions were not granted.

This change adds the necessary permissions to the `release` job
in the `release.yml` workflow file, allowing it to create releases
successfully.

Author: google-labs-jules[bot]

.github/workflows/release.yml

@@ -16,6 +16,8 @@ on:
 jobs:
   release:
     runs-on: ubuntu-latest
+    permissions:
+      contents: write
     steps:
       - name: Create Release
         id: create_release