ENH: Add fix-nightly-warnings skill and CDash query scripts

[blowekamp]

Summary

Adds a GitHub Copilot agent skill for the workflow of fixing ITK nightly build warnings reported on CDash, along with two helper Python scripts for querying the CDash GraphQL API.

Changes

• SKILL.md — Skill definition describing the step-by-step procedure: fetch nightly build warnings from CDash, identify warning patterns, apply minimal source fixes, build affected modules to verify, and open a draft PR.
• list_nightly_warnings.py — CLI script to list recent CDash nightly builds and their warning counts via the GraphQL API.
• get_build_warnings.py — CLI script to fetch and display detailed warning messages for a specific CDash build ID via the GraphQL API.

Notes

No production source changes; purely development tooling.

[blowekamp]

I have had some success with this skill. Adding the scripts is a way to reduce the number of requests needed for the AI, and improve efficiency. I have am running low on available requests with the initial development of this skill.

Someone else is welcome to further refine this workflow.

[dzenanz]

Looks good on a glance.

[thewtex]

Very cool!!

We may want to set up a GitHub Agentic Workflow to run this on a regular basis.

[thewtex]

opens -> open

[hjmjohnson]

@blowekamp I have some improvements ready for this PR (typo fixes, ThirdParty filtering, MSVC warning support, a triage_nightly.py entry point, etc.).

To let me push directly to your PR branch, could you enable "Allow edits from maintainers"? You can do this by:

1. Scrolling to the bottom of this PR page
2. Checking the box "Allow edits and access to secrets by maintainers"

(This option is in the right sidebar under the PR description when you're editing the PR, or at the bottom of the PR creation/edit page.)

Once enabled, I'll be able to git push to your fork's skill_fix_nightly_warnings branch directly. Alternatively, I can close this PR and open a new one from upstream/skill_fix_nightly_warnings where I've already pushed the changes — let me know your preference.

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FYI: I asked claude to make separate commits with recommendations to make this skill more automated and efficient:

https://github.com/InsightSoftwareConsortium/ITK/tree/skill_fix_nightly_warnings

The 10 commits should probably be squished, but they seem reasonable for draft consideration.

[blowekamp]

That option is already enabled.