test: removes redundant dev image from python test

FROM registry.gitlab.com/notno/poetry as poetry

COPY pyproject.toml poetry.lock /

RUN poetry export --without-hashes --output /requirements.txt

RUN poetry export --dev --without-hashes --output /requirements-dev.txt

FROM python:slim as base

WORKDIR /install

COPY --from=poetry /requirements.txt /requirements-dev.txt .

COPY --from=poetry /requirements.txt .

COPY mypackage /project

FROM base as dev

RUN pip install -r requirements-dev.txt

WORKDIR /project

COPY tests .

FROM base

RUN pip install -r requirements.txt

RUN pip-review --auto