ci: move from get-poetry to install-poetry script

get-poetry.py is deprecated and will be removed in the future.
Currently update to poetry 1.2 is still not possible.
See python-poetry/poetry#4187

Closes https://gitlab.gistools.geog.uni-heidelberg.de/giscience/heigit-disaster-portal/-/issues/20

dap_api/Dockerfile

@@ -9,7 +9,7 @@ ENV GUNICORN_CMD_ARGS="--reload"
 ARG DEV
 
 # Install Poetry
-RUN curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | POETRY_HOME=/opt/poetry python && \
+RUN curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/install-poetry.py | POETRY_HOME=/opt/poetry python && \
     cd /usr/local/bin && \
     ln -s /opt/poetry/bin/poetry && \
     poetry config virtualenvs.create false