Reverse the order and abort on error so I don't have to wait for a long run if the latest solution has an error.

.github/workflows/solve.yaml

@@ -17,7 +17,8 @@ jobs:
       - uses: https://github.com/fwilhe2/setup-kotlin@main
       - name: Solutions
         run: |
-          for script in $(ls *.kts | sort); do
+          set -e
+          for script in $(ls *.kts | sort -r); do
             echo "Running $script"
             kotlin $script
           done