update poetry

Author: valentin-gauthier-geosiris

.github/actions/prepare-poetry/action.yml

@@ -37,7 +37,7 @@ runs:
     - name: Install Poetry
       uses: snok/install-poetry@v1
       with:
-        version: 1.5.1
+        version: 2.1.1
         virtualenvs-create: true
         virtualenvs-in-project: true