Update CHANGELOG.md for 11.7.0

[ci skip]

changelogs/unreleased/winh-princess-mononospace.yml

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-title: Make commit IDs in merge request discussion header monospace
-merge_request: 23562
-author:
-type: changed

changelogs/unreleased/winh-upgrade-gitlab-ui.yml

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-title: Upgrade @gitlab/ui to 1.16.2
-merge_request: 23946
-author:
-type: other

changelogs/unreleased/zj-backup-restore-object-pools.yml

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-title: Restore Object Pools when restoring an object pool
-merge_request: 23682
-author:
-type: added