fix: docker 이미지 이름 수정

.github/workflows/back-media-cd.yml

@@ -65,7 +65,7 @@ jobs:
       - name: 🐳 Docker 빌드 및 푸시
         run: |
           echo "Starting Docker build..."
-          docker buildx build -f apps/media/Dockerfile . 
+          docker buildx build -f apps/media/Dockerfile . -t my-media-app
           echo "Docker build completed."
 
       - name: 🐳 Docker 실행