revert: add default styling for GlInputGroupText

mentioned in commit 2e4d4089

mentioned in merge request gitlab-org/frontend/pajamas-adoption-scanner!186 (merged)

mentioned in merge request status-page!859 (merged)

mentioned in merge request gitlab!126562 (merged)

mentioned in merge request gitlab-org/gitlab-services/design.gitlab.com!3432 (merged)

mentioned in merge request gitlab-docs!4182 (merged)

mentioned in merge request status-page!862 (merged)

mentioned in merge request gitlab!129862 (closed)

mentioned in merge request gitlab-org/frontend/pajamas-adoption-scanner!197 (merged)

mentioned in merge request gitlab!130154 (merged)

mentioned in merge request gitlab-docs!4196 (merged)

mentioned in merge request gitlab-org/gitlab-services/design.gitlab.com!3508 (merged)

mentioned in merge request gitlab-docs!4197 (merged)

mentioned in merge request gitlab-docs!4198 (closed)