[no-ci] CI: drive restricted paths guard from user-in-org-check-bot

[rwgk]

Related issue: #1139

Depends on the paired github-apps PR 78 that adds and deploys user-in-org-check-bot.

TODO before merging:

• switch .github/workflows/restricted-paths-guard.yml back from pull_request to pull_request_target
• remove the temporary # XXX DUMMY CHANGE XXX line from cuda_bindings/pyproject.toml

Summary

This PR is the cuda-python half of the rollout for the new user-in-org-check-bot.

It adds repository config for the new bot and rewrites .github/workflows/restricted-paths-guard.yml to consume explicit bot-managed PR-author membership labels instead of relying on author_association.

What changes

• add .github/user-in-org-check-bot.yaml to configure user-in-org-check-bot for NVIDIA/cuda-python
• update restricted-paths-guard.yml to recognize these terminal membership labels:
  • PR-Author-In-NVIDIA-Org
  • PR-Author-Outside-NVIDIA-Org
  • PR-Author-Org-Check-Failure
• keep Needs-Restricted-Paths-Review as the policy label for confirmed non-member PRs that touch cuda_bindings/ or cuda_python/
• fail the workflow on operational problems (to cleanly avoid guessing)
• only re-evaluate on labeled / unlabeled events when one of the membership-bot labels changes

Workflow behavior

For PRs that do not touch restricted paths, the guard exits green.

For PRs that touch restricted paths, the guard now works as follows:

• if Needs-Restricted-Paths-Review is already present, exit quickly and leave it sticky for manual removal
• if PR-Author-In-NVIDIA-Org is already present, exit quickly and pass
• if PR-Author-Outside-NVIDIA-Org is already present, ensure Needs-Restricted-Paths-Review is present and finish green
• if PR-Author-Org-Check-Failure is already present, fail with guidance to rerun later or apply a manual override label
• otherwise, poll live PR labels for up to about 60 seconds waiting for a terminal bot result
• if no terminal result appears within that window, fail
• if both PR-Author-In-NVIDIA-Org and PR-Author-Outside-NVIDIA-Org are present at the same time, fail explicitly because the state is inconsistent

Why this shape

• It separates the authoritative org-membership question from the repo-specific policy decision.
• It avoids false positives from author_association.
• It keeps the rescue path obvious in pathological cases:
  • maintainers can manually apply PR-Author-In-NVIDIA-Org
  • maintainers can manually apply PR-Author-Outside-NVIDIA-Org
  • maintainers can still manage Needs-Restricted-Paths-Review manually if needed
• It avoids catch-22 behavior by keeping manual intervention possible when the bot or workflow is unavailable.

Scope boundary

This PR does not make Needs-Restricted-Paths-Review merge-blocking by itself.

That remains intentionally separate from the guard logic. The follow-on gate PR, #1896, handles the merge-blocking status check so the policy and enforcement pieces can be reviewed independently.

Testing note

Because Probot repo config is read from the default branch, the full end-to-end behavior with the deployed app cannot be exercised from this PR alone before merge.

To make the workflow logic testable in this PR:

• the trigger is temporarily changed from pull_request_target to pull_request
• cuda_bindings/pyproject.toml includes a temporary dummy line so the PR definitely touches a restricted path
• PR labels can be manipulated manually to simulate the bot outcomes

Test plan

• Open a PR from this branch and confirm the temporary pull_request trigger runs.
• With no terminal bot label present, confirm the guard times out after about 60 seconds and fails.
• Add PR-Author-In-NVIDIA-Org and confirm the guard succeeds quickly without adding Needs-Restricted-Paths-Review.
• Add PR-Author-Outside-NVIDIA-Org and confirm the guard adds Needs-Restricted-Paths-Review and succeeds.
• Add PR-Author-Org-Check-Failure and confirm the guard fails with rerun/manual-override guidance.
• Add both PR-Author-In-NVIDIA-Org and PR-Author-Outside-NVIDIA-Org and confirm the guard fails with an explicit conflicting-label error.
• Before merge, remove the dummy change and switch the workflow trigger back to pull_request_target.

[copy-pr-bot]

Auto-sync is disabled for draft pull requests in this repository. Workflows must be run manually.

Contributors can view more details about this message here.

[rwgk]

Closing: github-apps PR 78 did not receive direct feedback, an alternative PR 79 is on track to provide a different solution.