libc++ 19 removed the generic std::char_traits, which basic_string<uint16be>
needs. Take the definition already here for Apple Clang 17 on libc++ too.

--- a/src/util/helpers/StringHelpers.h
+++ b/src/util/helpers/StringHelpers.h
@@ -2,8 +2,9 @@
 #include "boost/nowide/convert.hpp"
 #include <charconv>
 
-// Definition for removed templates in Apple Clang 17
-#if defined(__apple_build_version__) && (__apple_build_version__ >= 17000000)
+// Definition for removed templates in Apple Clang 17 and libc++ 19
+#if (defined(__apple_build_version__) && (__apple_build_version__ >= 17000000)) || \
+	(defined(_LIBCPP_VERSION) && _LIBCPP_VERSION >= 190000)
 namespace std {
 	template<>
 	struct char_traits<uint16be> {