fix: keep relative symlinks inside the copied fixture - #12

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5, jdx/mise-action@60119f926c4aeea4f9d22e43a9a090b920e2e418. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/