Description

Resolves error preventing aten::stack from converting correctly with dynamic shapes. Unsqueezed dims used 0 for dynamic dimension which was not aligned correctly with the dynamic dim in the input, switch to using -1.
Fixes # (issue)

Type of change

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• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the style guidelines of this project (You can use the linters)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas and hacks
• I have made corresponding changes to the documentation
• I have added tests to verify my fix or my feature
• New and existing unit tests pass locally with my changes
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