Update poetry version

Author: nielsdebruin

.github/workflows/ci.yml

@@ -44,7 +44,7 @@ jobs:
       - name: Install Poetry
         uses: snok/install-poetry@v1
         with:
-          version: 1.9.1
+          version: 1.8.1
           plugins: poetry-plugin-export
 
       - name: build-java