Add explicit permissions to docs workflow

(cherry picked from commit ac30219a6a0eb9f98798da39ddef7fe554e43616)

.github/workflows/docs.yml

@@ -4,6 +4,9 @@ on:
   push:
     branches: [release-v*]
 
+permissions:
+  contents: write
+
 jobs:
   build:
     runs-on: ubuntu-latest