build(github): display mockery diff for debugging

.github/workflows/check-generated.yml

@@ -35,7 +35,7 @@ jobs:
           curl -sL "https://github.com/vektra/mockery/releases/download/v${MOCKERY}/mockery_${MOCKERY}_Linux_x86_64.tar.gz" | tar -C /usr/local/bin -xzf -
           make mockery 2>/dev/null
 
-          if ! git diff --stat --exit-code ; then
+          if ! git diff --exit-code ; then
             echo ">> ERROR:"
             echo ">>"
             echo ">> Generated mocks require update (either Mockery or source files may have changed)."