[release-2.1] chore: add release-2.1 to publish branch options - #229

On November 2, 2026, GitHub will restrict `pull_request_target` on public repositories by default. To continue allowing the event trigger, configure an Actions policy. Learn more: https://gh.io/securely-using-pull_request_target#default-policy-for-pull_request_target

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: amannn/action-semantic-pull-request@0723387faaf9b38adef4775cd42cfd5155ed6017, marocchino/sticky-pull-request-comment@52423e01640425a022ef5fd42c6fb5f633a02728. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/