Update release notes

cowtowncoder · cowtowncoder · commit 695ca3f79c53 · 2024-03-27T17:20:42.000-07:00
diff --git a/release-notes/VERSION-2.x b/release-notes/VERSION-2.x
@@ -16,7 +16,8 @@ a pure JSON library.
 
 2.18.0 (not yet released)
 
--
+#1252: `ThreadLocalBufferManager` replace synchronized with `ReentrantLock`
+ (contributed by @pjfanning)
 
 2.17.1 (not yet released)
 
