Switch to Debian based images for Python cryptography

Dockerfile

-FROM python:3-alpine AS python_build
+FROM python:3 AS python_build
 COPY requirements-prod.txt /requirements.txt
-RUN apk add --no-cache build-base git \
- python3-dev openssl-dev libffi-dev xmlsec xmlsec-dev \
- postgresql-dev mariadb-connector-c-dev \
- jpeg-dev zlib-dev freetype-dev lcms2-dev openjpeg-dev \
- tiff-dev \
- && pip install -r /requirements.txt
+RUN apt-get update \
+ && apt-get install -y --no-install-recommends \
+      python3-dev libxmlsec1 libxmlsec1-dev \
+      libpq-dev libmariadb-dev \
+ && rm -rf /var/cache/apt
+RUN pip install -r /requirements.txt
 
 FROM node:alpine AS assets_build
 RUN apk add --no-cache python make g++
@@ -14,9 +14,12 @@ RUN yarn install --pure-lockfile
 COPY assets /assets
 RUN /node_modules/.bin/webpack-cli
 
-FROM python:3-alpine
-RUN apk add --no-cache xmlsec postgresql-libs mariadb-connector-c \
- zlib freetype jpeg openjpeg tiff lcms2 \
+FROM python:3-slim
+RUN apt-get update \
+ && apt-get install -y --no-install-recommends \
+      zlib1g libfreetype6 libjpeg62-turbo libopenjp2-7 libtiff5 liblcms2-2 \
+      libpq5 libmariadb3 libxmlsec1 \
+ && rm -rf /var/cache/apt \
  && mkdir /app
 WORKDIR /app