Qualcomm AI Engine Direct - Preserve partition metadata on single-output delegate getitem nodes (#20805)

### Summary
The single-output path in `create_submodule_from_nodes` copied only
"val" onto the manually-built getitem, dropping other partition meta
(e.g. QNN's `q_tensor_io` tag) that the multi-output path keeps via
`propagate_meta`, leaving backend IO-tagging passes with wrong delegate
`dtype`/`spec`.

Fix by propagating full meta then dropping
`nn_module_stack`/`source_fn_stack`, matching the multi-output path.