depends: Update libmultiprocess library before converting to subtree

Bring in a few cmake changes to improve cmake support and fix compile/lint/tidy warnings.

bitcoin-core/libmultiprocess#140 build: don't clobber user/superproject c++ version
bitcoin-core/libmultiprocess#142 build: add option for external mpgen binary
bitcoin-core/libmultiprocess#143 cleanup: initialize vars in the EventLoop constructor in the correct order
bitcoin-core/libmultiprocess#146 cmake: Suppress compiler warnings from capnproto headers
bitcoin-core/libmultiprocess#147 cmake: EXTERNAL_MPGEN cleanups
bitcoin-core/libmultiprocess#148 util: fix -Wpessimizing-move warning
bitcoin-core/libmultiprocess#145 CTest: Module must be included at the top level
bitcoin-core/libmultiprocess#149 Avoid `-Wundef` compiler warnings
bitcoin-core/libmultiprocess#152 refactor: Fix compiler and clang-tidy warnings
bitcoin-core/libmultiprocess#155 scripted-diff: s/Libmultiprocess_EXTERNAL_MPGEN/MPGEN_EXECUTABLE/g
bitcoin-core/libmultiprocess#156 refactor: Remove locale-dependent function calls
bitcoin-core/libmultiprocess#157 refactor: Avoid using std::format
bitcoin-core/libmultiprocess#159 bugfix: Do not lock EventLoop::mutex after EventLoop is done

Author: ryanofsky

depends/packages/native_libmultiprocess.mk

@@ -1,8 +1,8 @@
 package=native_libmultiprocess
-$(package)_version=07c917f7ca910d66abc6d3873162fc9061704074
+$(package)_version=26b9f3dda42110a8ffa5e81b0ea78ba1e30ae659
 $(package)_download_path=https://github.com/chaincodelabs/libmultiprocess/archive
 $(package)_file_name=$($(package)_version).tar.gz
-$(package)_sha256_hash=ac9db311e3b22aac3c7b7b7b3f6b7fee5cf3043ebb3c3bf412049e8b17166de8
+$(package)_sha256_hash=08e9715841cb4049c3b7c49f592dfaa59a4f7863395c632fa484435e701cf304
 $(package)_dependencies=native_capnp
 
 define $(package)_config_cmds