sys: Remove remaining references to hex.builtin from libimhex

main/include/init/splash_window.hpp

@@ -23,8 +23,6 @@ namespace hex::init {
             this->m_tasks.emplace_back(taskName, task);
         }
 
-        [[nodiscard]] const std::string &getGPUVendor() const { return this->m_gpuVendor; }
-
     private:
         GLFWwindow *m_window;
         std::mutex m_progressMutex;