Finalize changelog for 2.21.0

Signed-off-by: bwest981 <[email protected]>

Author: Bwest981

.changeset/pink-singers-greet.md

@@ -1,6 +1,6 @@
 # Changelog Chainlink Core
 
-## 2.21.0 - UNRELEASED
+## 2.21.0 - 2025-02-27
 
 ### Minor Changes
 
@@ -90,6 +90,8 @@
 
 - [#15977](https://github.com/smartcontractkit/chainlink/pull/15977) [`d2fa4bcbbf`](https://github.com/smartcontractkit/chainlink/commit/d2fa4bcbbfe783844238dcd33cb0813fac06d4d4) - #added a new way to calculate CCIP gas deviation thresholds using a sliding curve approach
 
+- [#16417](https://github.com/smartcontractkit/chainlink/pull/16417) [`1bbddbf048`](https://github.com/smartcontractkit/chainlink/commit/1bbddbf04878dbe0b3c000679822d612842b968b) - fixes inability to approve multiple jobs with same command for standard capabilities
+
 ## 2.20.0 - 2025-01-30
 
 ### Minor Changes