Clarify change to port names in v6.10.0 (#1411)

Clarified the update regarding port names and service meshes in Kubernetes, adding additional instructions for users of Istio and Envoy filters.

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Author: marcleblanc2

docs/admin/updates/kubernetes.mdx

@@ -14,7 +14,7 @@ For upgrade procedures or general info about sourcegraph versioning see the link
 
 ## v6.10.0
 
-- Port names have been updated to unblock Kubernetes service meshes from auto-configuring themselves for the traffic type, since most inter-pod communication has been switched from http to gRPC [[PR 756](https://github.com/sourcegraph/deploy-sourcegraph-helm/pull/756)]
+- Port names have been updated on services and pods, to unblock Kubernetes service meshes from auto-configuring themselves for the traffic type, since most inter-pod communication has been switched from http to gRPC [[PR 756](https://github.com/sourcegraph/deploy-sourcegraph-helm/pull/756)]. If you are using Istio (or similar service meshes), and [our Envoy filter example](https://github.com/sourcegraph/deploy-sourcegraph-helm/tree/main/charts/sourcegraph/examples/envoy), and your pods fail to communicate after upgrading to >= v6.10, please remove the Envoy filter and try again so your service mesh can auto-configure itself based on the new port names.
 
 ## v6.4.0