Update .gitreview for unmaintained/2024.1

Change-Id: I18ba3839164bbf57238a1b482e47ac00aac94856
Signed-off-by: OpenStack Release Bot <[email protected]>
Generated-By: openstack/project-config:roles/copy-release-tools-scripts/files/release-tools/functions

Author: openstackadmin

.gitreview

@@ -2,4 +2,4 @@
 host=review.opendev.org
 port=29418
 project=openstack/cloudkitty-dashboard.git
-defaultbranch=stable/2024.1
+defaultbranch=unmaintained/2024.1