chore(deps): bump postcss from 8.5.16 to 8.5.18 - #646

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v2, github/codeql-action/analyze@v3, github/codeql-action/autobuild@v3, github/codeql-action/init@v3. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

The setup-python-dependencies input is deprecated and no longer has any effect. We recommend removing any references from your workflows. See https://github.blog/changelog/2024-01-23-codeql-2-16-python-dependency-installation-disabled-new-queries-and-bug-fixes/ for more information.