T8966: add legacy-label escape to invalid-task-id rule (commit check exempt)

[andamasov]

Adds a maintainer-controlled legacy label escape to the per-repo T-ID rule (toggles invalid-task-id). The PR title check stays enforced for every PR; the per-commit check is exempted when a PR carries the legacy label — an escape hatch for grandfathered PRs whose commit history cannot be rewritten (repos that squash-merge and block force-push). Pilot verified on vyos/vyos.vyos. Change-management: IS-539. Tracked under T8966.

🤖 Generated by robots

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository YAML (base), Central YAML (inherited), Organization UI (inherited)

Review profile: CHILL

Plan: Pro

Run ID: a7d81fc8-c144-4ef9-ac79-33bf63b0f033

📥 Commits

Reviewing files that changed from the base of the PR and between 5db51cd and 71450e5.

📒 Files selected for processing (1)

• .github/mergify.yml

---

📝 Walkthrough

Summary by CodeRabbit

• Chores
  • Updated internal pull request validation configuration.

Walkthrough

Mergify rule for T-ID format validation updated to exempt PRs with a legacy label. The commit message format check is now gated under an and: condition requiring both commit-message nonconformance and the absence of a legacy label before flagging the invalid-task-id label.

Changes

Mergify T-ID Validation Exemption

Layer / File(s)	Summary
T-ID check exemption gate .github/mergify.yml	The commits[*].commit_message pattern check is wrapped with and: [label!=legacy], exempting legacy-labeled PRs from T-ID format validation and subsequent invalid-task-id labeling.

Possibly related PRs

• vyos/ipaddrcheck#42: Earlier PR implementing the product T-ID title/commit-message Mergify rule that this PR refines with label-based exemption logic.

✨ Finishing Touches

✨ Simplify code

• Create PR with simplified code
• Commit simplified code in branch feat/T8966-legacy-escape

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}