Isolate pip install steps in Dockerfile

Dockerfile

@@ -22,9 +22,11 @@ RUN apt-get update && apt-get install -y --no-install-recommends openjdk-17-jre-
 
 # 4. Python 의존성 설치
 COPY requirements.txt .
-RUN pip install --no-cache-dir --upgrade pip && \
-    pip install --no-cache-dir -r requirements.txt && \
-    echo "--- Checking uvicorn and PATH ---" && \
+RUN pip install --no-cache-dir --upgrade pip
+
+RUN pip install --no-cache-dir -r requirements.txt
+
+RUN echo "--- Checking uvicorn and PATH ---" && \
     which uvicorn && \
     echo "PATH is: $PATH" && \
     echo "--- End of check ---"