No more TypeVar

TypeVar are not suitable for method only type checking

libs/lib/xaal/lib/types.py

-# Python type hints for the xAAL library
-
-from typing import TYPE_CHECKING, TypeVar
-
-if TYPE_CHECKING:
-    from .devices import Device, Attributes, Attribute
-    from .engine import Engine
-    from .aioengine import AsyncEngine
-    from .bindings import UUID
-
-DeviceT = TypeVar("DeviceT", bound="Device")
-AttributeT = TypeVar("AttributeT", bound="Attribute")
-AttributesT = TypeVar("AttributesT", bound="Attributes")
-EngineT = TypeVar("EngineT", bound="Engine")
-AsyncEngineT = TypeVar("AsyncEngineT", bound="AsyncEngine")
-
-UUIDT = TypeVar("UUIDT", bound="UUID")