Prep for 2.21.0 release

Author: cowtowncoder

pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.fasterxml.jackson</groupId>
     <artifactId>jackson-base</artifactId>
-    <version>2.21.0-SNAPSHOT</version>
+    <version>2.21.0</version>
   </parent>
   <groupId>com.fasterxml.jackson.dataformat</groupId>
   <artifactId>jackson-dataformats-binary</artifactId>

release-notes/VERSION-2.x

@@ -14,7 +14,7 @@ Active maintainers:
 === Releases ===
 ------------------------------------------------------------------------
 
-2.21.0 (not yet released)
+2.21.0 (18-Jan-2026)
 
 #599: (cbor) Unable to deserialize stringref-enabled CBOR with ignored properties
  (reported by Yohei K)