[mlir][python] Fix segfault in DenseResourceElementsAttr.get_from_buffer for 0-d tensors (#183070)
When `ndim == 0`, `view->strides[view->ndim - 1]` is an out-of-bounds
access (unsigned underflow to `SIZE_MAX`). Use `view->itemsize` for
alignment instead, since a scalar buffer is trivially aligned to its
element size.
Fixes iree-org/iree-turbine#1312.