Add docker install URL for 28.0 (#5231)

Co-authored-by: Evgeniya Vashkevich <evgeniya.vashkevich@suse.com>

Author: github-actions[bot]

lib/shared/addon/components/form-engine-opts/component.js

@@ -51,6 +51,10 @@ export default Component.extend({
         label: 'v28.1.x',
         value: 'https://releases.rancher.com/install-docker/28.1.sh'
       },
+      {
+        label: 'v28.0.x',
+        value: 'https://releases.rancher.com/install-docker/28.0.sh'
+      },
       {
         label: 'v27.5.x',
         value: 'https://releases.rancher.com/install-docker/27.5.sh'