Update release notes

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -13,7 +13,7 @@ NOTE: Annotations module will never contain changes in patch versions,
 
 2.19.0 (not yet released)
 
-No changes since 2.18
+#280: Minor change to `module-info.java`: use "open module"
 
 2.18.0 (26-Sep-2024)