Enable Layout/TrailingWhitespace cop and auto-correct offenses

See merge request !13573

* upstream/master: (62 commits)
  Update gitlab.po: Missing 'r' in "Fouché" that comes from "Fourcher" verb.
  Docs: update user docs index
  Fix minor typos in views
  Fix Layout/SpaceBeforeBlockBraces violation in bin/changelog_spec
  Merge branch 'rs-alphanumeric-ssh-params' into 'security-9-4'
  Merge branch 'import-symlinks-9-3' into 'security-9-3'
  Fix wrong method call on prometheus histogram
  Document new all-in-one Helm chart - docs
  Fix 404 on link path
  Fix line numbers not matching up to code in code viewer.
  Hide overflow-x on collapsed sidebar
  removed global use of breakpoint checker
  Increase performance of the breakpoint size checker
  Filter sensitive query string parameters from NGINX access logs
  Added a template for database changes
  Render new issue link in failed job as a regular link instead of a UJS one
  Include RE2 in the upgrade docs
  Remove affix plugin from issuable sidebar with new navigation
  Fix linter error
  alternative route for download archive
  ...

Its usage has been removed at 2fa22a0729.

* master: (86 commits)
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  33874 confidential issue redesign
  Exclude merge_jid on Import/Export attribute configuration
  Resolve "User dropdown in filtered search does not load avatar on `master`"
  Re-add column locked_at on migration rollback
  Group-level new issue & MR using previously selected project
  [EE Backport] Update log audit event in omniauth_callbacks_controller.rb
  more eagerly bail when the state is prevented
  Move locked_at removal to post-deployment migration
  Add class to other sidebars
  Improve mobile sidebar
  reduce iterations by keeping a count of remaining enablers
  Store & use ConvDev percentages returned by Version app
  Store MergeWorker JID on merge request, and clean up stuck merges
  Backport changes in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/2551 to CE
  DRY up caching in AbstractReferenceFilter
  Update CHANGELOG
  Add CHANGELOG entry
  Fix html structure Removes test for removed behavior
  Port form back to use form_tag
  ...