Irrlicht cleanups (mostly getting rid of core::array)

Co-authored-by: Lars Müller <34514239+appgurueu@users.noreply.github.com>

irr/include/SMaterial.h

@@ -6,7 +6,6 @@
 
 #include "SColor.h"
 #include "matrix4.h"
-#include "irrArray.h"
 #include "irrMath.h"
 #include "EMaterialTypes.h"
 #include "EMaterialProps.h"