upgrade python_multipart version for demo

Dockerfile

@@ -18,7 +18,7 @@ RUN pip install --no-cache-dir .
 # Install additional dependencies for demo.py
 RUN pip install --no-cache-dir \
     uvicorn[standard]==0.29.0 \
-    python-multipart==0.0.9 \
+    python-multipart==0.0.20 \
     httpx==0.27.0 \
     opentelemetry-api==1.34.1 \
     opentelemetry-sdk==1.34.1 \

demo.py

@@ -232,7 +232,7 @@ async def get_documents():
 #    ```
 #    fastapi==0.111.0
 #    uvicorn[standard]==0.29.0
-#    python-multipart==0.0.9
+#    python-multipart==0.0.20
 #    httpx==0.27.0
 #    opentelemetry-api==1.25.0
 #    opentelemetry-sdk==1.25.0

requirements.txt

@@ -1,6 +1,6 @@
 fastapi==0.111.0
 uvicorn[standard]==0.29.0
-python-multipart==0.0.9
+python-multipart==0.0.20
 httpx==0.27.0
 opentelemetry-api==1.34.1
 opentelemetry-sdk==1.34.1