Validate LayerNormalization axis bounds (#32555)
This pull request addresses validation and testing improvements for the
`LayerNormalization` operator, specifically handling invalid axis
values. The main change ensures that the operator correctly detects and
reports an error when the `axis` attribute exceeds the input tensor's
rank. Additionally, a new unit test is added to verify this behavior.
**Validation logic update:**
* Updated the axis validation in `onnx/defs/nn/defs.cc` to check if
`axis` is less than 0 or greater than or equal to the input tensor rank,
and to fail shape inference with an appropriate error message if so.
**Unit testing:**
* Added a new test case `LayerNorm_AxisExceedsRank` in
`onnxruntime/test/contrib_ops/layer_norm_op_test.cc` to ensure that
providing an out-of-bounds axis value results in a failure with the
expected error message.
