mensautils: improve caching

mensautils/Dockerfile

@@ -3,14 +3,15 @@ FROM debian:bullseye
 RUN apt update
 RUN apt -y --no-install-recommends install python3 python3-pip python3-setuptools python3-wheel gcc make uwsgi uwsgi-plugin-python3 libldap2-dev libldap-2.4-2 libsasl2-dev libsasl2-2 python3-dev
 
+ADD mensa-utils/requirements.txt /app/requirements.txt
+
+RUN pip3 install django-ldapdb django-auth-ldap sentry-sdk -r /app/requirements.txt
+
 COPY mensa-utils /app/src
 RUN rm -rf /app/src/.pyenv
 
 WORKDIR /app/src
 
-RUN pip3 install -r requirements.txt
-RUN pip3 install psycopg2-binary django-ldapdb django-auth-ldap sentry-sdk
-
 RUN ln -sf /app/config/settings.py /app/src/mensautils/settings.py
 
 COPY uwsgi-mensautils.ini /etc/uwsgi/mensautils.ini