Revert "Update python Docker tag to v3.12.3" (#1107)

This reverts commit f85e18f.

Dockerfile

@@ -6,7 +6,7 @@ WORKDIR /src
 RUN yarn install --frozen-lockfile --ignore-engines --prefer-offline && \
     node node_modules/webpack/bin/webpack.js --config  webpack.config.prod.js --bail
 
-FROM python:3.12.3-bullseye AS base
+FROM python:3.9.19-bullseye AS base
 # Add package files, install updated node and pip
 WORKDIR /tmp