Update mypy.ini from skeleton

Author: Avasam

mypy.ini

@@ -1,17 +1,27 @@
 [mypy]
-# CI should test for all versions, local development gets hints for oldest supported
-# But our testing setup doesn't allow passing CLI arguments, so local devs have to set this manually.
-# python_version = 3.8
+## upstream
+
+# Is the project well-typed?
 strict = False
+
+# Early opt-in even when strict = False
 warn_unused_ignores = True
 warn_redundant_casts = True
-# required to support namespace packages: https://github.com/python/mypy/issues/14057
+enable_error_code = ignore-without-code
+
+# Support namespace packages per https://github.com/python/mypy/issues/14057
 explicit_package_bases = True
 
 disable_error_code =
 	# Disable due to many false positives
 	overload-overlap,
 
+## local
+
+# CI should test for all versions, local development gets hints for oldest supported
+# But our testing setup doesn't allow passing CLI arguments, so local devs have to set this manually.
+# python_version = 3.8
+
 exclude = (?x)(
 	# Avoid scanning Python files in generated folders
 	^build/