Update ci.yml

Author: kingthorin

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
     - run: |
         python -m pip install --upgrade pip
         pip install setuptools
-        pipx install poetry==1.8.0
+        pipx install poetry==1.7.0
     - run: poetry install
     - run: poetry run pylama
     - run: poetry run py.test