docs: add release-notes

docs/release-notes/release-notes-0.18.4.md

@@ -23,6 +23,10 @@
   cause a nil pointer dereference during the probing of a payment request that
   does not contain a payment address.
 
+* [Fixed a bug](https://github.com/lightningnetwork/lnd/pull/9324) to prevent
+  potential deadlocks when LND depends on external components (e.g. aux
+  components, hooks).
+
 # New Features
 
 The main channel state machine and database now allow for processing and storing