Potential fix for code scanning alert no. 4: Workflow does not contain permissions

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: simongdavies

.github/workflows/ci.yml

@@ -1,6 +1,8 @@
 # yaml-language-server: $schema=https://json.schemastore.org/github-action.json
 
 name: CI
+permissions:
+  contents: read
 
 on:
   push: