Fix flash-attn build by installing packaging early

Dockerfile

@@ -15,6 +15,8 @@ RUN apt-get update && apt-get install -y \
 # Update pip
 RUN pip install --upgrade pip
 
+RUN pip install packaging
+
 # Copy requirements.txt and install dependencies
 COPY requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
@@ -33,3 +35,4 @@ EXPOSE 7860
 
 # Run the FastAPI app
 CMD ["python", "main.py"]
+