chore: release 1.5.21

Author: aws-sdk-kotlin-ci

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## [1.5.21] - 08/19/2025
+
+### Features
+* (**cleanrooms**) Support error message configuration for analysis templates
+* (**ec2**) Add support for "warning" volume status.
+* (**polly**) Added support for new output format - Opus.
+
 ## [1.5.20] - 08/18/2025
 
 ### Features

gradle.properties

@@ -6,7 +6,7 @@ kotlin.native.ignoreDisabledTargets=true
 org.gradle.jvmargs=-Xmx10g -XX:MaxMetaspaceSize=2G
 
 # sdk
-sdkVersion=1.5.21-SNAPSHOT
+sdkVersion=1.5.21
 
 # dokka config (values specified at build-time as needed)
 smithyKotlinDocBaseUrl=https://sdk.amazonaws.com/kotlin/api/smithy-kotlin/api/$smithyKotlinRuntimeVersion/