Fix reshape bug (support for opset version 1)

[antimora]

Pull Request Template

Checklist

• Confirmed that run-checks all script has been executed.
• Made sure the book is up to date with changes in this PR.

Related Issues/PRs

#1593

Changes

1. Use shape attribute

Testing

Pytorch supports opset 7+ so I could not recreate the ONNX file but I was able to use the onnx from #1593

[codecov]

Codecov Report

Attention: Patch coverage is 79.16667% with 5 lines in your changes are missing coverage. Please review.

Project coverage is 86.41%. Comparing base (6c70852) to head (2551635).
Report is 1 commits behind head on main.

Files	Patch %	Lines
crates/burn-import/src/onnx/dim_inference.rs	79.16%	5 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1667   +/-   ##
=======================================
  Coverage   86.41%   86.41%           
=======================================
  Files         694      694           
  Lines       80676    80666   -10     
=======================================
- Hits        69718    69710    -8     
+ Misses      10958    10956    -2     

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[laggui]

Minor comments on form, otherwise LGTM! Approving in advance.