Move poetry caching to a writeable dir in development image

Author: Themitchell

Dockerfile

@@ -79,11 +79,12 @@ RUN apt-get update && apt-get install -y \
 
 ENV POETRY_NO_INTERACTION=1 \
     POETRY_VIRTUALENVS_IN_PROJECT=1 \
-    POETRY_VIRTUALENVS_CREATE=1
+    POETRY_VIRTUALENVS_CREATE=1 \
+    POETRY_CACHE_DIR=/tmp/poetry_cache
 
 COPY pyproject.toml poetry.lock ./
 RUN pip install poetry
-RUN poetry install --no-root
+RUN poetry install --no-root && rm -rf $POETRY_CACHE_DIR
 RUN poetry run playwright install --with-deps chromium
 
 USER ${USER}