feat: CI checks ands blocks PR for linked issue

[nv-dmendoza]

Is this a new feature, an enhancement, or a change to existing functionality?

New Feature

How would you describe the priority of this feature request

Medium

Please provide a clear description of problem this feature solves

Pull requests can currently be opened and merged without referencing any issue. When a PR has no linked issue, changes are harder to track in things like milestones.

Feature Description

As a maintainer, I want every pull request to reference a linked issue, so that all code changes are traceable to an issue. CI will reject any pull request whose title or body contains no issue reference.

Describe your ideal solution

1. Add issue requirement in CONTRIBUTING.md and the PR template
2. Add a CI status check job that parses the PR title/body for an issue reference, fails when not found

Describe any alternatives you have considered

No response

Additional context

No response

Code of Conduct

• I agree to follow NVIDIA Infra Controller's Code of Conduct
• I have searched the open feature requests and have found no duplicates for this feature request

[ajf]

When a PR has no linked issue, changes are harder to track in things like milestones.

PRs can have milestones, and they should be self-describing enough to have enough info why it was done.

The real thing that we actually lose without liking a PR to an issue is the project tracking and QA lifecycle that we've built into GitHub projects.

For a change like #2648, a separate issue just seems like unnecessary overhead. Is that a tradeoff we want to make?