Longhorn: Upgrade from 1.7.3 to 1.8.1

Change-Id: Ie2076df97ee3d00cbced65ad52888d3b467725d4
diff --git a/charts/longhorn/Chart.yaml b/charts/longhorn/Chart.yaml
index 04c937b..07777a4 100644
--- a/charts/longhorn/Chart.yaml
+++ b/charts/longhorn/Chart.yaml
@@ -1,5 +1,5 @@
 apiVersion: v1
-appVersion: v1.7.3
+appVersion: v1.8.1
 description: Longhorn is a distributed block storage system for Kubernetes.
 home: https://github.com/longhorn/longhorn
 icon: https://raw.githubusercontent.com/cncf/artwork/master/projects/longhorn/icon/color/longhorn-icon-color.png
@@ -11,7 +11,7 @@
 - device
 - iscsi
 - nfs
-kubeVersion: '>=1.21.0-0'
+kubeVersion: '>=1.25.0-0'
 maintainers:
 - email: maintainers@longhorn.io
   name: Longhorn maintainers
@@ -25,4 +25,4 @@
 - https://github.com/longhorn/longhorn-ui
 - https://github.com/longhorn/longhorn-tests
 - https://github.com/longhorn/backing-image-manager
-version: 1.7.3
+version: 1.8.1