Import TypedDict from typing_extensions

While typing has a TypedDict class from Python 3.8, pydantic requires the use of typing_extensions prior to 3.12.

Author: rwb27

src/labthings_fastapi/properties.py

@@ -55,11 +55,10 @@ class attribute. Documentation is in strings immediately following the
     Callable,
     Generic,
     TypeVar,
-    TypedDict,
     overload,
     TYPE_CHECKING,
 )
-from typing_extensions import Self
+from typing_extensions import Self, TypedDict
 from weakref import WeakSet
 
 from fastapi import Body, FastAPI