Merge branch '60304-long-file-names-in-mr-diffs-cause-horizontal-scrolling' into 'master'
Resolve "Long file names in MR diffs cause horizontal scrolling"
Closes #60304
See merge request gitlab-org/gitlab-ce!27233
(cherry picked from commit 225ddd14)
5b2b9fe0 Only make margin-auto on large screens for diff file header