fix(core/dropdown-button): accessibility consistency in dropdown-button - #2585

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, tj-actions/changed-files@2f7c5bfce28377bc069a65ba478de0a74aa0ca32. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/