ci: fix release creation permissions

Per https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/controlling-permissions-for-github_token,
`contents: write` is required to create new releases and upload artifacts.

Author: malor

.github/workflows/release.yml

@@ -40,7 +40,7 @@ jobs:
   build_assets:
     permissions:
       id-token: write
-      contents: read
+      contents: write
       attestations: write
 
     needs: create_release