Fix Layout/ArgumentAlignment offenses in spec/diff

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/135575



Merged-by: John Mason <9717668-johnmason@users.noreply.gitlab.com>
Approved-by: Vladlena Shumilo <vshumilo@gitlab.com>
Approved-by: John Mason <9717668-johnmason@users.noreply.gitlab.com>
Co-authored-by: Vitali Tatarintev <vtatarintev@gitlab.com>