onnxruntime

Fix crash in PadFusion (#18557)

### Description
This makes a minimal change to address a crash caused by the PadFusion
pass. This pass assumed that the "pads" attribute of a child node
existed, and it now skips when it's missing.



### Motivation and Context
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Co-authored-by: Jeff Bloomfield <38966965+jeffbloo@users.noreply.github.com>