chore: bump snapshot version to 0.31.1-SNAPSHOT

Author: aws-sdk-kotlin-ci

gradle.properties

@@ -6,7 +6,7 @@ kotlin.native.ignoreDisabledTargets=true
 org.gradle.jvmargs=-Xmx6g -XX:MaxMetaspaceSize=2G
 
 # sdk
-sdkVersion=0.31.0-beta
+sdkVersion=0.31.1-SNAPSHOT
 
 # codegen
 smithyVersion=1.29.0