Rewrite rodio to pure JNI under dev.nucleusframework.rodio; drop souvlaki - #1

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, actions/setup-java@v4, gradle/actions/setup-gradle@v3. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Failed to restore gradle-home-v1|macOS|smoke[0bcc4c154d993460cf128cd42644bdd4]-8f247dac2fa6b1323c3daf79a4f50175583d6d9e: Error: Cache service responded with 400