It may be useful to update before merge

getting-started/pull-request-lifecycle.rst

@@ -550,6 +550,10 @@ changes from the base branch (usually ``main``) into the PR.
 This is useful to :ref:`keep the CI green <keeping-ci-green>` for old PRs,
 or to check if a CI failure has been fixed in the base branch.
 
+If the PR is very old, it may be useful to update the branch before merging to
+ensure that the PR does not fail any CI checks that were added or changed since
+CI last ran.
+
 Do not click :guilabel:`Update branch` without a good reason because it notifies
 everyone watching the PR that there are new changes, when there are not,
 and it uses up limited CI resources.