Toyota: add 2026 Sienna firmware - #3713

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache@v4, dawidd6/action-download-artifact@v6, thollander/actions-comment-pull-request@v2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/