onnxruntime

Fuse Pad even if Cast is present in-between (#21640)

### Description
This change enhances the existing Pad Fusion to fuse Pad even if a Cast
operator is present between Pad and Conv/MaxPool/AveragePool. It keeps
the Cast as it is.
<pre>
/*
 * Before Fusion:
 *     Pad
 *      |
 *    Cast (Optional)
 *      |
 *   Conv/MaxPool/AveragePool
 * 
 * After Fusion:
 *    Cast (Optional)
 *      |
 *   Conv/MaxPool/AveragePool
 */
</pre>


### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->