docs: Fix rich display render - #98

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

Failed to restore: "/usr/bin/tar" failed with error: The process '/usr/bin/tar' failed with exit code 2

setup-java v4 is deprecated and will no longer receive updates. Please migrate to actions/setup-java@v5.