Prepare for v4.21.0 release (#3437)

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Co-authored-by: Ramon Quitales <ramon@pulumi.com>

CHANGELOG.md

@@ -3,9 +3,11 @@
 
 ## Unreleased
 
-### Added
+## 4.21.0 (January 16, 2025)
+
+### Changed
 
-- Adding in pulumi-java v1.0.0
+- Upgrade `pulumi-java` to version `v1.0.0`  (<https://github.com/pulumi/pulumi-kubernetes/pull/3436>)
 
 ## 4.20.0 (January 14, 2025)