3.13.0 release notes: mention Erlang 26 TLS default changes

Author: michaelklishin

release-notes/3.13.0.md

@@ -171,6 +171,16 @@ connect to the same node, or inject a pause, or await a certain condition that i
 is in place.
 
 
+### TLS Defaults
+
+Starting with Erlang 26, client side [TLS peer certificate chain verification](https://www.rabbitmq.com/docs/ssl#peer-verification) settings are enabled by default in most contexts:
+from federation links to shovels to TLS-enabled LDAP client connections.
+
+If using TLS peer certificate chain verification is not practical or necessary, it can be disabled.
+Please refer to the docs of the feature in question, for example,
+this one [on TLS-enabled LDAP client](http://rabbitmq.com/docs/ldap/#tls) connections.
+
+
 ### Management Plugin and HTTP API
 
 GET /api/queues` HTTP API endpoint has dropped several rarely used metrics, resulting in up to 25% in traffic saving.