Merge branch 'redacting-changelog' into 'master'

Added changelog entry for redacting improvements

See merge request !4896

CHANGELOG

@@ -16,6 +16,7 @@ v 8.9.1
   - Improve performance of searching repository tags by name by using a memorized tag array
   - Fix false truncated warnings with ISO-8559 files
   - Fix unwanted label unassignment when doing bulk action on issues page
+  - Improve performance of redacting Markdown references
   - Fix 404 when accessing pipelines as guest user on public projects
   - Fix mobile Safari bug where horizontal nav arrows would flicker on scroll
   - Fix in auto merge when pipeline is nil