Remove unneeded stuff

Author: shepazon

swift/example_code/identity-resolvers/cognito-resolver/Package.swift

@@ -33,7 +33,6 @@ let package = Package(
             dependencies: [
                 .product(name: "AWSCognitoIdentity", package: "aws-sdk-swift"),
                 .product(name: "AWSIAM", package: "aws-sdk-swift"),
-                .product(name: "AWSSTS", package: "aws-sdk-swift"),
                 .product(name: "AWSS3", package: "aws-sdk-swift"),
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
             ],

swift/example_code/identity-resolvers/cognito-resolver/Sources/Example.swift

@@ -4,7 +4,6 @@
 // snippet-start:[swift.identity.cognito.imports]
 import AWSCognitoIdentity
 import AWSSDKIdentity
-import AWSSTS
 // snippet-end:[swift.identity.cognito.imports]
 import AWSIAM
 import AWSS3

swift/example_code/identity-resolvers/cognito-resolver/Sources/entry.swift

@@ -10,7 +10,6 @@ import AWSCognitoIdentity
 import AWSIAM
 import AWSS3
 import AWSSDKIdentity
-import AWSSTS
 import Foundation
 import SmithyIdentity
 // snippet-end:[swift.identity.cognito.imports]