fix(GlDuoChat): Prevent scrolling the content behind the Duo Chat

mentioned in commit 72b7693a

mentioned in merge request gitlab-org/editor-extensions/gitlab-jetbrains-plugin!1212 (closed)

mentioned in merge request gitlab-org/frontend/playground/accessibility-scanner!55 (closed)

mentioned in merge request gitlab-org/frontend/pajamas-adoption-scanner!352 (merged)

mentioned in merge request status-page!903

mentioned in merge request gitlab!171616 (merged)

mentioned in commit ddc0e6a4

mentioned in merge request gitlab!171667 (closed)

mentioned in merge request gitlab!171760 (closed)

mentioned in commit 703ce824

mentioned in merge request gitlab-org/gitlab-services/design.gitlab.com!4168 (merged)

mentioned in merge request gitlab!172328 (closed)

mentioned in merge request gitlab-org/editor-extensions/gitlab-jetbrains-plugin!1249 (closed)

mentioned in merge request gitlab-org/frontend/playground/accessibility-scanner!58 (merged)