fix(ci): grant contents: write so sync-studies-index can push to main

Made-with: Cursor

Author: assassin808

.github/workflows/sync-studies-index.yml

@@ -9,6 +9,8 @@ on:
 jobs:
   rebuild:
     runs-on: ubuntu-latest
+    permissions:
+      contents: write
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5