Update CHANGELOG.md for v28.3.0 (#635)

Author: deividaspetraitis

CHANGELOG.md

@@ -35,10 +35,11 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 # Changelog
 
-## Unreleased
+## v28.3.0
 
 - Remove dependency on keyring, wire in CosmosSigner and grab private key from SQS_PRIVATE_KEY environment variable.
 - #632 - E-697 | Increase max routes for pricing worker
+- #633 - BE-707 | Skip processing quote requests when system is not healthy 
 
 ## v28.2.0