[doc] Add release notes for removed getpeerinfo fields.

doc/release-notes.md

@@ -63,6 +63,11 @@ P2P and network changes
 
 Updated RPCs
 ------------
+- `getpeerinfo` no longer returns the following fields: `addnode`, `banscore`,
+  and `whitelisted`, which were previously deprecated in 0.21. Instead of
+  `addnode`, the `connection_type` field returns manual. Instead of
+  `whitelisted`, the `permissions` field indicates if the peer has special
+  privileges. The `banscore` field has simply been removed. (#20755)
 
 Changes to Wallet or GUI related RPCs can be found in the GUI or Wallet section below.