Deprecation using in parameters

[o3o]

> dub build -q                                                                                                                                          
src/msgpack/unpacker.d(18,26): Deprecation: using `in` parameters with `extern(C)` functions is deprecated
src/msgpack/unpacker.d(18,26):        parameter `__anonymous_param` declared as `in` here

> dmd --version                                                                                                      
DMD64 D Compiler v2.105.0

Copyright (C) 1999-2023 by The D Language Foundation, All Rights Reserved written by Walter Bright
[I] [10:27:47] dao@abe /home/dao/d/msgpack-d

> dub --version                                                                                       
DUB version 1.34.0, built on Aug 28 2023

> git describe                                                                                                                                           
v1.0.4

see Using in parameters with non extern(D)/extern(C++) functions is deprecated

Thank you