Add base kubernetes support final fix 2

services/forecasting/Dockerfile

@@ -1,5 +1,5 @@
 # Add this stage at the top of each service Dockerfile
-FROM python:3.11-slim as shared
+FROM python:3.11-slim AS shared
 WORKDIR /shared
 COPY shared/ /shared/
 
@@ -27,7 +27,7 @@ COPY --from=shared /shared /app/shared
 COPY services/forecasting/ .
 
 # Add shared libraries to Python path
-ENV PYTHONPATH="/app:/app/shared:$PYTHONPATH"
+ENV PYTHONPATH="/app:/app/shared:${PYTHONPATH:-}"
 
 # Expose port
 EXPOSE 8000