Prep for 2.21.0 release

Author: cowtowncoder

pom.xml

@@ -3,7 +3,7 @@
   <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.module</groupId>
   <artifactId>jackson-modules-java8</artifactId>

release-notes/VERSION-2.x

@@ -8,7 +8,7 @@ Modules:
 === Releases ===
 ------------------------------------------------------------------------
 
-2.21.0 (not yet released)
+2.21.0 (18-Jan-2026)
 
 #359: `InstantDeserializer` deserializes the nanosecond portion of fractional
   negative timestamps incorrectly