check build file

.github/workflows/backend-build-alpha-image.yml

@@ -24,6 +24,8 @@ jobs:
         run: chmod +x gradlew
       - name: Build with Gradle
         run: ./gradlew build
+      - name: check jar file
+        run: ls -l build/libs
       - uses: actions/checkout@v3
       - name: Build Image
         run: docker build .