Update main.yml

Author: mcbarton

.github/workflows/main.yml

@@ -347,7 +347,7 @@ jobs:
             nbdiff notebooks/smallpt.ipynb $HOME/Downloads/smallpt.ipynb
             rm $HOME/Downloads/smallpt.ipynb  
           fi
-        timeout-minutes: 12
+        timeout-minutes: 13
 
       - name: Setup tmate session
         if: ${{ failure() && runner.debug }}