Bump github.com/stretchr/testify from 1.11.1 to 1.12.0 - #233

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, ravsamhq/notify-slack-action@v2, supplypike/setup-bin@v3. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/