dry run on test pypi

Author: agoscinski

.github/workflows/cd.yml

@@ -100,7 +100,7 @@ jobs:
             run: pip install flit~=3.4
 
         -   name: Build and publish
-            run: flit publish
+            run: flit publish --repository testpypi
             env:
                 FLIT_USERNAME: __token__
                 FLIT_PASSWORD: ${{ secrets.PYPI_KEY }}