docs: move istio to troubleshooting (#1097)

Co-authored-by: toast-gear <[email protected]>

README.md

@@ -1096,17 +1096,6 @@ spec:
         fsGroup: 1000
 ```
 
-
-### Use with Istio
-
-Istio 1.7.0 or greater has `holdApplicationUntilProxyStarts` added in https://github.com/istio/istio/pull/24737, which enables you to delay the `runner` container startup until the injected `istio-proxy` container finish starting. Try using it if you need to use Istio. Otherwise the runner is unlikely to work, because it fails to call any GitHub API to register itself due to `istio-proxy` being not up and running yet.
-
-Note that there's no official Istio integration in actions-runner-controller. It should work, but it isn't covered by our acceptance test (a contribution to resolve this is welcomed). In addition to that, none of the actions-runner-controller maintainers use Istio daily. If you need more information, or have any issues using it, refer to the following links:
-
-- https://github.com/actions-runner-controller/actions-runner-controller/issues/591
-- https://github.com/actions-runner-controller/actions-runner-controller/pull/592
-- https://github.com/istio/istio/issues/11130
-
 ### Stateful Runners
 
 > This feature requires controller version => [v0.20.0](https://github.com/actions-runner-controller/actions-runner-controller/releases/tag/v0.20.0)

TROUBLESHOOTING.md

@@ -43,6 +43,8 @@ runner Runner listener exit with retryable error, re-launch runner in 5 seconds.
 This is because the `istio-proxy` has not completed configuring itself when the
 configuration script tries to communicate with the network.
 
+More broadly, there are many other circumstances where the runner pod coming up first can cause issues.
+
 **Solution**<br />
 
 > Added originally to help users with older istio instances.
@@ -95,4 +97,4 @@ NETWORK=$(gcloud compute instances list --format='text(networkInterfaces[0].netw
 # 3) Get the master source ip block
 SOURCE=$(gcloud container clusters describe <cluster-name> --region <region> | grep masterIpv4CidrBlock| cut -d ':' -f 2 | tr -d ' ')
 gcloud compute firewall-rules create k8s-cert-manager --source-ranges $SOURCE --target-tags $WORKER_NODES_TAG  --allow TCP:9443 --network $NETWORK
-```
+```