Bumped poetry to 2.1.1 (#2103)

Author: RobertSamoilescu

Dockerfile

@@ -4,9 +4,7 @@ SHELL ["/bin/bash", "-l", "-c"]
 LABEL vendor="SeldonIO"
 LABEL maintainer="hello@seldon.io"
 
-# TODO: Upgrade poetry version to 2.x
-# Currently it fails in `poetry export --with all-runtimes --without-hashes --format constraints.txt -o /opt/mlserver/dist/constraints.txt`
-ARG POETRY_VERSION="1.8.5"
+ARG POETRY_VERSION="2.1.1"
 
 COPY ./hack/build-wheels.sh ./hack/build-wheels.sh
 COPY ./mlserver ./mlserver