Update MAISI model URL (#2051)

Fixes # .

### Description
A few sentences describing the changes proposed in this pull request.

### Checks
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Avoid including large-size files in the PR.
- [x] Clean up long text outputs from code cells in the notebook.
- [x] For security purposes, please check the contents and remove any
sensitive info such as user names and private key.
- [x] Ensure (1) hyperlinks and markdown anchors are working (2) use
relative paths for tutorial repo files (3) put figure and graphs in the
`./figure` folder
- [ ] Notebook runs automatically `./runner.sh -t <path to .ipynb file>`

---------

Signed-off-by: Can-Zhao <canz@nvidia.com>
Signed-off-by: Yun Liu <yunl@nvidia.com>
Signed-off-by: root <root@pool0-01907.cm.cluster>
Signed-off-by: Can-Zhao <volcanofly@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Yun Liu <yunl@nvidia.com>
Co-authored-by: root <root@pool0-01907.cm.cluster>