4cb14bef47
When `from __future__ import annotations` is active or forward references are used as strings, type annotations are not directly class objects. This change uses `get_type_hints` to resolve these string annotations to their actual types, ensuring correct validation of message handler signatures. PiperOrigin-RevId: 942608060 Change-Id: Ic2b214ee85e835616cc3a18ec2699eba6deebb6a