debug: dont manually unlock the lock_guard (#7210)

when lock_guard goes out of scope it RAII itself and calls unlock.
causes crashes on freebsd/libc++ and double unlocking a mutex is UB.

src/debug/Log.hpp

@@ -72,6 +72,5 @@ namespace Debug {
         logMsg += std::vformat(fmt.get(), std::make_format_args(args...));
 
         log(level, logMsg);
-        logMutex.unlock();
     }
 };