Merge branch '509302-refactor-ancestors_tree-vue-to-use-design-tokens' into 'master'

Migrate ancestors_tree to use variants on gl-icons

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/175707



Merged-by: Mark Florian <mflorian@gitlab.com>
Approved-by: Mark Florian <mflorian@gitlab.com>
Reviewed-by: Mark Florian <mflorian@gitlab.com>
Co-authored-by: James Rushford <jrushford@gitlab.com>