[macOS/iOS] Set MoltenVK logging level based on `--verbose` flag.

main/main.cpp

@@ -1956,6 +1956,10 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 		OS::get_singleton()->_verbose_stdout = GLOBAL_GET("debug/settings/stdout/verbose_stdout");
 	}
 
+#if defined(MACOS_ENABLED) || defined(IOS_ENABLED)
+	OS::get_singleton()->set_environment("MVK_CONFIG_LOG_LEVEL", OS::get_singleton()->_verbose_stdout ? "3" : "1"); // 1 = Errors only, 3 = Info
+#endif
+
 	if (frame_delay == 0) {
 		frame_delay = GLOBAL_DEF(PropertyInfo(Variant::INT, "application/run/frame_delay_msec", PROPERTY_HINT_RANGE, "0,100,1,or_greater"), 0);
 	}