misc: remove InternalApi annotation from AwsSigningResult

Author: 0marperez

runtime/auth/aws-signing-common/common/src/aws/smithy/kotlin/runtime/auth/awssigning/AwsSigningResult.kt

@@ -4,13 +4,10 @@
  */
 package aws.smithy.kotlin.runtime.auth.awssigning
 
-import aws.smithy.kotlin.runtime.InternalApi
-
 /**
  * The result of an AWS signing operation
  * @param T The type of the result
  */
-@InternalApi
 public data class AwsSigningResult<T>(
     /**
      * The signed output.