Remove nlohmann/json_fwd includes

include/mtx/events/voip.hpp

 #pragma once
 
-#if __has_include(<nlohmann/json_fwd.hpp>)
-#include <nlohmann/json_fwd.hpp>
-#else
 #include <nlohmann/json.hpp>
-#endif
 
 #include <string>
 #include <vector>

include/mtx/responses/turn_server.hpp

@@ -3,11 +3,7 @@
 #include <string>
 #include <vector>
 
-#if __has_include(<nlohmann/json_fwd.hpp>)
-#include <nlohmann/json_fwd.hpp>
-#else
 #include <nlohmann/json.hpp>
-#endif
 
 namespace mtx::responses {