Add convolution registrar entry for int4 without implementation - Need for generate scheduling

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

@@ -268,6 +268,9 @@ REGISTRAR(ConvImpl2D_cpu,
 REGISTRAR(ConvImpl2D_cpu,
     {{DataType::Any, DataFormat::NCHW}, {DataType::Int32, DataFormat::NCHW}},
     {ProdConso::inPlaceModel, Aidge::ConvImpl2D_cpu_forward_kernel<int32_t, int32_t, int32_t, int32_t>, nullptr});
+REGISTRAR(ConvImpl2D_cpu,
+    {{DataType::Any, DataFormat::NCHW}, {DataType::Int4, DataFormat::NCHW}},
+    {ProdConso::inPlaceModel, nullptr, nullptr});
 REGISTRAR(ConvImpl2D_cpu,
     {{DataType::Any, DataFormat::NCHW}, {DataType::Float64, DataFormat::NCHW}},
     {ProdConso::inPlaceModel, Aidge::ConvImpl2D_cpu_forward_kernel<double, double, double, double>, nullptr});