Bump actions/setup-node from 6 to 7 - #164

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: gsactions/commit-message-checker@4c06ad2446942246543ef9c50f672a58782bf7b0. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/