fix(longhorn): upgrade to v1.11.1, fix 38GB instance-manager memory leak

v1.11.0 had a critical proxy connection leak in the instance-manager
(longhorn/longhorn#12575) that consumed 38.8GB on apollo, pushing the
server to 92% memory with swap exhausted.

v1.11.1 fixes the leak. Also adds a 2Gi per-container LimitRange in
longhorn-system as a safety net against future regressions.

base/longhorn/kustomization.yaml

@@ -7,7 +7,7 @@ resources:
 helmCharts:
   - name: longhorn
     repo: https://charts.longhorn.io
-    version: "1.11.0"
+    version: "1.11.1"
     releaseName: longhorn
     namespace: longhorn-system
     valuesFile: values.yaml