fix(windows): disable fmtlib's utf-8 support to compile

Author: Tom94

CMakeLists.txt

@@ -285,7 +285,9 @@ set(BUILD_SHARED_LIBS OFF)
 
 if (TCNN_EXTERNAL_FMT)
 	list(APPEND TCNN_LIBRARIES "${TCNN_EXTERNAL_FMT}")
+	list(APPEND TCNN_DEFINITIONS -DFMT_UNICODE=0)
 else()
+	set(FMT_UNICODE OFF CACHE BOOL " " FORCE)
 	add_subdirectory("dependencies/fmt")
 	list(APPEND TCNN_LIBRARIES fmt)
 	list(APPEND TCNN_INCLUDES "dependencies/fmt/include")