changelog: add notes about closing #13600

[skip ci]

CHANGELOG.md

@@ -27,6 +27,7 @@
 * **Stackdriver/Cloudwatch**: Allow user to change unit in graph panel if cloudwatch/stackdriver datasource response doesn't include unit [#13718](https://github.com/grafana/grafana/issues/13718), thx [@mtanda](https://github.com/mtanda)
 * **Stackdriver**: stackdriver user-metrics duplicated response when multiple resource types [#13691](https://github.com/grafana/grafana/issues/13691)
 * **Variables**: Fix text box template variable doesn't work properly without a default value [#13666](https://github.com/grafana/grafana/issues/13666)
+* **Variables**: Fix variable dependency check when using `${var}` format [#13600](https://github.com/grafana/grafana/issues/13600)
 * **Dashboard**: Fix kiosk=1 url parameter should put dashboard in kiosk mode [#13764](https://github.com/grafana/grafana/pull/13764)
 * **LDAP**: Fix super admins can also be admins of orgs [#13710](https://github.com/grafana/grafana/issues/13710), thx [@adrien-f](https://github.com/adrien-f)