Potential fix for code scanning alert no. 55: Workflow does not contain permissions (#631)

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

Author: andykenward

.github/workflows/check-dist.yml

@@ -6,6 +6,8 @@
 # For our project, we generate this file through a build process from other source files.
 # We need to make sure the checked-in `index.js` actually matches what we expect it to be.
 name: check dist
+permissions:
+  contents: read
 
 on:
   push: