fixup mypy pyproject options

Author: llucax

tests_golden/integration/test_cookiecutter_generation/api/frequenz-api-test/pyproject.toml

@@ -131,6 +131,11 @@ disable = [
 [tool.pytest.ini_options]
 testpaths = ["pytests"]
 
+[tool.mypy]
+explicit_package_bases = true
+namespace_packages = true
+strict = true
+
 [tool.setuptools.package-dir]
 "" = "py"