Recognize forward references inside TypeAliasType for Python 3.12

It appears that the `type` statement in Python 3.12 generates [`TypeAliasType` objects at runtime](https://docs.python.org/3/library/typing.html#typing.TypeAlias) which are similar to the existing `ForwardRef` objects which trycast() already needs to understand to follow forward-references to types.

