Adding GAMSPy transportation model example as Jupyter notebook

[0x17]

Description

This PR adds an example notebook for using cuOpt as solver in a Jupyter notebook of the classic transportation model written in GAMSPy.

I created this as a draft, as the PR has some prerequisites:

• The repository for the solver link cuoptlink-builder must be set to public beforehand and this will be timed with the publication of a GAMS blog article on the link.
• A counterpart PR for the cuopt repository should ideally be merged shortly after as it mentions the added example here.

Issue

Part of resolving #188

[rgsl888prabhu]

Left few minor comments. Thank you for the notebook.

@chris-maes any suggestions

[rgsl888prabhu]

@0x17 Changes look awesome, rest of the notebook looks good. I am approving the PR assuming you will address the last few comments.

[rgsl888prabhu]

minor comment, just need to add license to end of the notebook under markdown

SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved. SPDX-License-Identifier: MIT Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

[rgsl888prabhu]

I should add this instruction to README.md, apologies for more requests.

[rgsl888prabhu]

Thank you @0x17