updated the frontend docker file with the main branch

Author: Dhruvkumar-Microsoft

src/frontend/Dockerfile

@@ -33,7 +33,11 @@ COPY pyproject.toml requirements.txt* uv.lock* ./
 
 # Install Python dependencies using UV
 RUN --mount=type=cache,target=/root/.cache/uv \
-    uv pip install --system pyproject.toml && uv pip install --system "uvicorn[standard]"; \
+    if [ -f "requirements.txt" ]; then \
+      uv pip install --system -r requirements.txt && uv pip install --system "uvicorn[standard]";  \
+    else \
+      uv pip install --system pyproject.toml && uv pip install --system "uvicorn[standard]"; \
+    fi
 
 # Stage 3: Final production image
 FROM python:3.11-slim-bullseye