Move build-arg so it's avaiable

Author: hc2p

python/base/Dockerfile.python

@@ -1,3 +1,4 @@
+ARG CIRCLE_PULL_REQUEST
 FROM debian:bullseye-slim AS builder
 
 # Install dependencies for building Python
@@ -32,7 +33,7 @@ RUN wget -qO- "https://www.python.org/ftp/python/${PYTHON_VERSION_PATCH}/Python-
     && make -j "$(nproc)" \
     && make altinstall
 
-ARG CIRCLE_PULL_REQUEST
+
 FROM deepnote/python:base${CIRCLE_PULL_REQUEST:+-ra-${CIRCLE_PULL_REQUEST##*/}}
 # Copy Python from the builder stage
 ARG PYTHON_VERSION