Merge #22921: Some small improvements to release notes

9f9ffe5 Some small improvements to release notes (Pieter Wuille)

Pull request description:

  .

ACKs for top commit:
  laanwj:
    ACK 9f9ffe5
  dongcarl:
    ACK 9f9ffe5

Tree-SHA512: 63ff574eb1c5e7b5f2ac4fc99d3352d2de7fa05ccd0abbe58fcc0720b139ace05c855a6cf46ab7a5537b3f0792442d98dc155c3f3ee7bfd1127fe08f5fb01be5

doc/release-notes.md

@@ -57,8 +57,8 @@ P2P and network changes
 - Added NAT-PMP port mapping support via
   [`libnatpmp`](https://miniupnp.tuxfamily.org/libnatpmp.html). (#18077)
 
-Updated RPCs
-------------
+New and Updated RPCs
+--------------------
 
 - Due to [BIP 350](https://github.com/bitcoin/bips/blob/master/bip-0350.mediawiki)
   being implemented, behavior for all RPCs that accept addresses is changed when
@@ -125,12 +125,12 @@ Updated RPCs
 
 Changes to Wallet or GUI related RPCs can be found in the GUI or Wallet section below.
 
-New RPCs
---------
-
 Build System
 ------------
 
+- Release binaries are now produced using the new `guix`-based build system.
+  The [/doc/release-process.md](/doc/release-process.md) document has been updated accordingly.
+
 Files
 -----