[master] Release notes for Istio 1.13.8 (#11898)

* Release notes for Istio 1.13.8

* Add a new release notes entry

* Fix lint

* Update the release date

Co-authored-by: Lei Tang <32078630+lei-tang@users.noreply.github.com>

content/en/news/releases/1.13.x/announcing-1.13.8/index.md

@@ -0,0 +1,30 @@
+---
+title: Announcing Istio 1.13.8
+linktitle: 1.13.8
+subtitle: Patch Release
+description: Istio 1.13.8 patch release.
+publishdate: 2022-09-12
+release: 1.13.8
+---
+
+This release contains bug fixes to improve robustness.
+This release note describes what’s different between Istio 1.13.7 and Istio 1.13.8.
+
+{{< relnote >}}
+
+## Changes
+
+- **Fixed** an issue where Istio did not update the list of endpoints in `STRICT_DNS` clusters during workload instance updates.  ([Issue #39505](https://github.com/istio/istio/issues/39505))
+
+- **Fixed** an issue where a service, with and without Virtual Service timeouts specified,
+  is incorrectly setting the timeouts.  ([Issue #40299](https://github.com/istio/istio/issues/40299))
+
+- **Fixed** an issue where `istiod` starts up very slowly when
+  connectivity to GCP metadata service is only partially broken.
+  ([Issue #40601](https://github.com/istio/istio/issues/40601))
+
+- **Fixed** an issue causing TLS `ServiceEntries` to sometimes not work when created after TCP ones.
+
+- **Fixed** an issue where `istioctl analyze` started showing invalid warning messages.
+
+- **Fixed** potential memory leak when updating hostname of service entries.