Dubbo 3.2.11, using the tri protocol, the interface must implement the Async method

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After upgrading to 3.2.11, the previously defined interface using PB method encountered compilation errors and required the implementation of Async method, which is not compatible with the defined interface. We hope this issue can be resolved.

Start by reproducing the compilation error with Dubbo 3.2.11, using the previously defined PB interface and the tri protocol. Trace where the generated or required Async method is introduced; done means the existing interface remains compatible without an unexpected implementation requirement, with a regression test if the relevant test location can be identified.

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