Fix manager types scope (#991)

* Fix manager types scope

* Restore incremental mode and mention in developer docs

* Separate dev mypy config and regular one

* Document config files usage

.github/workflows/test.yml

@@ -46,7 +46,7 @@ jobs:
           pip install -r ./requirements.txt
 
       - name: Run tests
-        run: pytest
+        run: pytest --mypy-ini-file=mypy.ini
 
   typecheck:
     runs-on: ubuntu-latest