feat(flaskapi): pin itis-sumo==0.1.0a4 (Dakota 6.24) — modernization rung 2 - #559

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/setup-node@v4, astral-sh/setup-uv@v3. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/