fix(GlListbox): fix dropdown positioning

mentioned in commit 3462f13c

mentioned in merge request status-page!627 (merged)

mentioned in merge request gitlab!102072 (merged)

mentioned in merge request gitlab!102214 (merged)

mentioned in merge request status-page!630 (merged)

mentioned in merge request gitlab-docs!3225 (merged)

mentioned in merge request gitlab-org/gitlab-services/design.gitlab.com!3109 (merged)

mentioned in merge request gitlab-org/frontend/pajamas-adoption-scanner!87 (merged)