FEAT(repo): add ignoreDiff for ServiceAccount

- to prevent sync ...
- Ignore resourceVersion, uid, and secrets for longhorn-service-account
- Prevents ArgoCD from recreating ServiceAccount during selfHeal
- Fixes instance-manager token mount failures on master node

longhorn/argocd.yaml

@@ -45,6 +45,13 @@ spec:
         goldilocks.fairwinds.com/enabled: 'true'
   revisionHistoryLimit: 10
   ignoreDifferences:
+  - group: ""
+    kind: ServiceAccount
+    name: longhorn-service-account
+    jsonPointers:
+    - /metadata/resourceVersion
+    - /metadata/uid
+    - /secrets
   - group: apiextensions.k8s.io
     kind: CustomResourceDefinition
     name: engines.longhorn.io