fix Slice attr type

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

@@ -32,9 +32,9 @@ void SliceImpl_cpu_forward_kernel(const typename Slice_Op::Attrs& attrs,
     DimSize_t nbAxes = std::get<2>(attrs).size();
     for (std::size_t i = 0; i < nbAxes; ++i) {
         // For each slice operation get the params and cast them to size_t
-        const std::int64_t axis_ = std::get<2>(attrs)[i];
-        const std::int64_t start_ = std::get<0>(attrs)[i];
-        const std::int64_t end_ = std::get<1>(attrs)[i];
+        const std::int32_t axis_ = std::get<2>(attrs)[i];
+        const std::int32_t start_ = std::get<0>(attrs)[i];
+        const std::int32_t end_ = std::get<1>(attrs)[i];
         const std::size_t axis = axis_ >= 0 ? axis_ : static_cast<std::size_t>(axis_) + inputDims.size();
         const std::size_t start = start_ >= 0 ? start_ : start_ + inputDims[axis];
         const std::size_t end = end_ >= 0 ? end_ : end_ + inputDims[axis];