chore: update smithy version to 1.22.0

## Motivation

awslabs/aws-sdk-swift#597 is failing due to unresolved shape `smithy.api#Unit` which was introduced in smithy-lang/smithy#980

## Changes

Updated smithyVersion to 1.22.0.

## Result

AWS SDK handles `smithy.api#Unit` for operation correctly.

Packages/ClientRuntime/Sources/Networking/Http/UnknownHttpServiceError.swift

@@ -4,7 +4,7 @@
  */
 
 /// General Service Error structure used when exact error could not be deduced from the `HttpResponse`
-public struct UnknownHttpServiceError: HttpServiceError {
+public struct UnknownHttpServiceError: HttpServiceError, Swift.Equatable {
     public var _isThrottling: Bool = false
 
     public var _statusCode: HttpStatusCode?

gradle.properties

@@ -3,7 +3,7 @@ kotlin.code.style=official
 # config
 
 # codegen
-smithyVersion=1.13.1
+smithyVersion=1.22.0
 smithyGradleVersion=0.5.3
 
 # kotlin

settings.gradle.kts

@@ -27,3 +27,4 @@ pluginManagement {
 rootProject.name = "smithy-swift"
 
 include("smithy-swift-codegen")
+include("smithy-swift-codegen-test")