Fix template compilation and warnings
Context
Compilation error when building with CUDA 12.6 and GCC 14.2
Modified files
include/aidge/backend/cuda/data/TensorImpl.hpp
src/data/TensorImpl.cu
src/operator/ILayerNormImpl_CUDA_kernels.cu
Detailed major modifications
Moved enable_if template specialization from parameter to return type which helps the compiler to select the correct implementation. Changed factor type to avoid out of bound warning.