Merge branch '481674-remove-unused-css-classes-from-pages-label' into 'master'

Audit list of classes in page_bundles/labels.scss

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/164638



Merged-by: Savas Vedova <svedova@gitlab.com>
Approved-by: Sascha Eggenberger <seggenberger@gitlab.com>
Approved-by: Anastasia Khomchenko <akhomchenko@gitlab.com>
Approved-by: Savas Vedova <svedova@gitlab.com>
Co-authored-by: Deepak kumar <kumar.deepak.iiit@gmail.com>