Remove unused header

code/AssetLib/3MF/D3MFOpcPackage.cpp

@@ -58,8 +58,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <memory>
 #include <vector>
 
-#include "contrib/stb/stb_image.h"
-
 namespace Assimp {
 
 namespace D3MF {