Update update_readme.yml

Author: jeremymanning

.github/workflows/update_readme.yml

@@ -8,6 +8,7 @@ on:
 jobs:
   update-readme:
     runs-on: ubuntu-latest
+    if: github.repository_owner == 'ContextLab'  # only run if on the ContextLab (source) repository!
 
     steps:
       - name: Checkout repository