[Backport release-24.05] vimPlugins.copilot-vim: fix meta attrs

[github-actions[bot]]

Bot-based backport to release-24.05, triggered by a label in #320699.

• [ ] Before merging, ensure that this backport is acceptable for the release.
  • Even as a non-commiter, if you find that it is not acceptable, leave a comment.

[GaetanLepage]

Will this end up in the nixos-24.05 channel ?