Lock poetry version

Done to fix poetry not fetching dependencies of dependencies of dependencies (abstract-iga-client->scim-client->cachetools) when installing with poetry install --no-dev --no-interaction --no-ansi

Dockerfile

@@ -3,7 +3,7 @@
 # To deal with this you have to forward the traffic through an ssh tunnel.
 # Luckily we have sshuttle. Forward your traffic before building the image by
 # running sshuttle -l 22 --remote <username>@<host> <subnet>
-FROM harbor.uio.no/library/python:3-slim
+FROM harbor.uio.no/library/docker.io-python:3-slim
 
 LABEL no.uio.contact=bnt-int@usit.uio.no
 
@@ -21,7 +21,7 @@ ENV PIP_DEFAULT_TIMEOUT=100 \
 RUN install -v -d -m 770 /var/log/cristin-ms
 
 # Get dependency manager
-RUN pip3 install poetry
+RUN pip3 install poetry==1.1.4
 
 # Copy files and install dependencies
 WORKDIR /cristin-ms