Update fetch_models.sh

[vd-nv]

What does the PR do?

The link to download the onnx model in the script is broken. This PR attempts a fix at that.

Checklist

• I have read the Contribution guidelines and signed the Contributor License
  Agreement
• PR title reflects the change and is of format <commit_type>: <Title>
• Changes are described in the pull request.
• Related issues are referenced.
• Populated github labels field
• Added test plan and verified test passes.
• Verified that the PR passes existing CI.
• I ran pre-commit locally (pre-commit install, pre-commit run --all)
• Verified copyright is correct on all changed files.
• Added succinct git squash message before merging ref.
• All template sections are filled out.
• Optional: Additional screenshots for behavior/output changes with before/after.

Commit Type:

Check the conventional commit type
box here and add the label to the github PR.

• build
• ci
• docs
• feat
• fix
• perf
• refactor
• revert
• style
• test

Related PRs:

NA

Where should the reviewer start?

Just one file

Test plan:

• Run the script to get the model
• Ran several client tests and the model works

Caveats:

NA

Background

The original link to download the model is dead.
Also another use raised this issue: #7608

Related Issues: (use one of the action keywords Closes / Fixes / Resolves / Relates to)

• closes GitHub issue: When downloading, execute ./fetch_models.sh the report #7608