notebooks: Added updated copyright footer

[validbeck]

Pull Request Description

What and why?

sc-13925

While adding the copyright info to the documentation files, we realised that the notebooks that are commonly dispersed to users as "capsule" files do not have this info. I updated:

• All the notebooks in notebooks minus the "mini-templates" that get pulled together by the end-to-end notebook generation notebook
• The copyright.txt file that contains the updated copyright info

How to test

Pull down this PR and click on any full notebook file. Jump to the bottom to see the updated copyright info:

For example:

• Quickstart for model documentation
• Validate an application scorecard model

What needs special review?

n/a

Dependencies, breaking changes, and deployment notes

• notebooks in docs: Added updated copyright footer documentation#1114 pulls these updated notebooks into the docs repo side
• https://github.com/validmind/demo-environment/pull/23 pulls these updated notebooks into the demo-environment side

Release notes

n/a

Checklist

• What and why
• Screenshots or videos (Frontend)
• How to test
• What needs special review
• Dependencies, breaking changes, and deployment notes
• Labels applied
• PR linked to Shortcut
• Unit tests added (Backend)
• Tested locally
• Documentation updated (if required)
• Environment variable additions/changes documented (if required)

[github-actions]

PR Summary

This pull request uniformly updates the copyright headers across a large number of files in the repository. The changes adjust the copyright years from "2023-2024" to "2023-2026" and modify the accompanying commentary to emphasize referring to the LICENSE file in the repository for details. These updates improve clarity and ensure that the copyright notices remain current without altering the runtime behavior or logic of the code.

Test Suggestions

• Run the full test suite (unit, integration, and end-to-end tests) to verify that no functionality has been inadvertently affected by the header changes.
• Perform a code search for any residual outdated copyright headers.
• Verify that documentation and automated tools that parse headers still function as expected.

[nrichers]

Copyright footer changes LGTM but AFAIK updating the copyright year to 2026 is not a hard requirement, as copyright doesn't magically expire. Still a nice change to have, though.

I left one comment about the wordiness of the copyright footer, please take a look. Unlike the Python files, which cannot link directly to the LICENSE file, the notebooks can use a link and so the text should not need to explain where to find the link target - that's the purpose of the link after all.

I assume you didn't check with a license scanning tool if this copyright footer gets found? I believe most modern license scanners will detect SPDX-License-Identifier in a Jupyter Notebook cell if it's in plain text, so this change should be OK. That said, if you can check, that might be useful.

[cachafla]

Wow, lots of files 😄

Awesome.