Remove unused Host import

I'm guessing this is a leftover from older days and that it has remained
since because of the noqa so it flew under the radar.

nornir/core/__init__.py

@@ -1,7 +1,7 @@
 import logging
 import logging.config
 import types
-from typing import TYPE_CHECKING, Any, Callable, Dict, Generator, List, Optional, Type
+from typing import Any, Callable, Dict, Generator, List, Optional, Type
 
 from nornir.core.configuration import Config
 from nornir.core.inventory import Inventory
@@ -10,9 +10,6 @@
 from nornir.core.state import GlobalState
 from nornir.core.task import AggregatedResult, Task
 
-if TYPE_CHECKING:
-    from nornir.core.inventory import Host  # noqa: W0611
-
 logger = logging.getLogger(__name__)