Use poetry 1.8.5 action

publish job installs previous version of this plugin which is atm
not available for poetry 2. So use poetry 1.8.5 to publish a poetry 2
compatible version of the plugin.

.github/workflows/build.yaml

@@ -30,6 +30,8 @@ jobs:
         with:
           fetch-depth: 0
       - uses: snok/install-poetry@v1
+        with:
+          version: 1.8.5
       - uses: actions/setup-python@v5
         with:
           python-version: "3.10"