TEST merge - release 13 9 - Do not merge into master

Why is this change being made?

See #10886 (closed)

To test (locally) merging master into the 13.9 release branch prior to the 22nd, and that this branch can be merged into a copy of master (master-for-rp-13-9) without conflict.

This is a copy of the release-13-9 branch (from Sunday 21st), checked out locally with master at 1688fcec merged into it, pushed, and then merged into a copy of master (master-for-rp-13-9). This tests the process we will use for the real release-13-9 branch to be merged into master on the 22nd.

Author Checklist

• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Assign this change to the correct DRI
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to one of the people listed in the "Maintained by" section in on the page being edited.
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies.
  • If the changes relate to any part of the project other than updates to content and/or data files please make sure to ping @gl-static-site-editor in a comment for a review and merge. For example changes to .gitlab-ci.yml, JavaScript/CSS/Ruby code or the layout files. (this requirement has been removed pending identification of a new DRI for the handbook)