ci: give permissions for cache-action

Author: inkydragon

.github/workflows/CI.yml

@@ -34,6 +34,11 @@ jobs:
   docs:
     name: Documentation
     runs-on: ubuntu-latest
+    permissions:
+      # needed to allow julia-actions/cache to proactively delete old caches that it has created
+      actions: write 
+      contents: write
+      statuses: write
     steps:
       - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v2