Fix handling of type params within type dict params.

Author: dnwpark

typemap/type_eval/_apply_generic.py

@@ -67,7 +67,8 @@ def dump(self, *, _level: int = 0):
 
 def substitute(ty, args):
     if isinstance(ty, dict):
-        return ty
+        # Handle typed dicts used as a type parameter
+        return {k: substitute(v, args) for k, v in ty.items()}
     elif ty in args:
         return args[ty]
     elif isinstance(ty, (typing_GenericAlias, types.GenericAlias)):