Update maven.yml

.github/workflows/maven.yml

@@ -27,7 +27,7 @@ jobs:
         
     - name: Check if JAR files exist
       run: |
-        if [ ! -d "target" ] || [ -z "$(ls -A target/*.jar)" ]; then
+        if ! [ -d "target" ] || ! [ "$(ls -A target/*.jar 2>/dev/null)" ]; then
           echo "No JAR files found in target directory or target directory does not exist."
           exit 1
         fi