fix(ci): add permissions for generate-manifests workflow

Author: CalvinAllen

.github/workflows/generate-manifests-from-r2.yml

@@ -25,6 +25,10 @@ on:
         default: false
         type: boolean
 
+permissions:
+  contents: write
+  pull-requests: write
+
 jobs:
   generate:
     name: Generate Manifests