fix(combobox): Combobox ARIA labeling

mentioned in commit 329c21f7

mentioned in merge request status-page!903

mentioned in merge request gitlab!183796 (merged)

mentioned in merge request gitlab-org/editor-extensions/gitlab-jetbrains-plugin!1571 (closed)

mentioned in merge request gitlab!183829 (merged)

mentioned in merge request gitlab-org/gitlab-services/design.gitlab.com!4332 (merged)

mentioned in merge request gitlab!184010 (closed)

mentioned in merge request gitlab-org/gitlab-services/design.gitlab.com!4345 (merged)

mentioned in merge request gitlab-org/gitlab-services/design.gitlab.com!4346 (merged)

mentioned in merge request gitlab-org/editor-extensions/gitlab-jetbrains-plugin!1591 (merged)

mentioned in merge request gitlab-org/frontend/playground/accessibility-scanner!67 (closed)

mentioned in merge request gitlab-org/frontend/pajamas-adoption-scanner!367 (merged)