[Fix] add missing ConvDepthWise forward include

include/aidge/backend/cpu/operator/ConvDepthWiseImpl_forward_kernels.hpp

@@ -17,6 +17,7 @@
 #include "aidge/backend/cpu/operator/ConvDepthWiseImpl.hpp"
 #include "aidge/utils/Types.h"
 #include <cmath>
+#include <cstddef>
 #include <array>
 #include <algorithm>