fix: Retry OnnxHub call to improve test reliability

[svotaw]

What changes are proposed in this pull request?

Make OnnxHub more reliable

[github-actions]

Hey @svotaw 👋!
Thank you so much for contributing to our repository 🙌.
Someone from SynapseML Team will be reviewing this pull request soon.

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[mhamilton723]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[codecov-commenter]

Codecov Report

Merging #1889 (777a83a) into master (412620a) will decrease coverage by 6.94%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1889      +/-   ##
==========================================
- Coverage   86.95%   80.02%   -6.94%     
==========================================
  Files         301      301              
  Lines       15565    15566       +1     
  Branches      797      795       -2     
==========================================
- Hits        13535    12457    -1078     
- Misses       2030     3109    +1079     

Impacted Files	Coverage Δ
.../com/microsoft/azure/synapse/ml/onnx/ONNXHub.scala	92.52% <100.00%> (+0.07%)	⬆️

... and 59 files with indirect coverage changes

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