Enable pyright for all Python 3 stubs (#5597)

* pyright: disable reportUnknownParameterType

Unknown parameter types are preferred over Any annotations for
incomplete stubs. Especially larger stubs are expected to be
incomplete for some time and it would be a shame to lose the
other pyright warnings for those stubs.

* Also disable reportUnknownVariableType

Fix problems with tkinter

* Disable reportUnknownMemberType

Fix pyright problems

stubs/PyYAML/yaml/composer.pyi

@@ -1,4 +1,4 @@
-from typing import Any, Dict, Optional, Union
+from typing import Any, Dict, Optional
 
 from yaml.error import MarkedYAMLError
 from yaml.nodes import MappingNode, Node, ScalarNode, SequenceNode