chore: disable cppcheck CI for treeland-protocols and fix typo (branc… - #801

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions-ecosystem/action-regex-match@v2, linuxdeepin/contributor-assistant-github-action@master. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/