Merge branch 'docs-uc-fix-usage-of-since-pt1' into 'master'

Docs: style update - replace `since` with `because` (part 1)

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/182924



Merged-by: Suzanne Selhorn <sselhorn@gitlab.com>
Co-authored-by: Uma Chandran <uchandran@gitlab.com>