Always echo matrix output

Author: tangrufus

action.yml

@@ -154,8 +154,9 @@ runs:
 
         echo ""
         echo "::group::===> Matrix Output"
-        echo "::stop-commands::STOP"
+        stopMarker=$(uuidgen)
+        echo "::stop-commands::$stopMarker"
         cat matrix
-        echo "::STOP::"
+        echo "::$stopMarker::"
         echo "::endgroup::"
       shell: bash