chore: Eliminate compile warnings in ClientRuntime and tests (#737)

Author: jbelkins

Sources/ClientRuntime/Endpoints/ServiceEndpointMetadata.swift

@@ -4,7 +4,6 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 //
-import ClientRuntime
 
 public struct ServiceEndpointMetadata {
     public let defaultProtocol = ProtocolType.https.rawValue

Sources/ClientRuntime/Endpoints/SmithyEndpoint.swift

@@ -4,7 +4,6 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 //
-import ClientRuntime
 
 /**
   A structure used by the service client to determine the endpoint.

Sources/ClientRuntime/Plugins/DefaultClientPlugin.swift

@@ -15,7 +15,7 @@ public class DefaultClientPlugin: Plugin {
         }
 
         if var config = clientConfiguration as? DefaultHttpClientConfiguration {
-            var httpClientConfiguration =
+            let httpClientConfiguration =
                 DefaultSDKRuntimeConfiguration<DefaultRetryStrategy, DefaultRetryErrorInfoProvider>
                     .defaultHttpClientConfiguration
             config.httpClientConfiguration = httpClientConfiguration

Tests/ClientRuntimeTests/NetworkingTests/Http/MiddlewareTests/FlexibleChecksumsMiddlewareTests.swift

@@ -176,7 +176,6 @@ class FlexibleChecksumsMiddlewareTests: XCTestCase {
 
     func testAlgorithmSelectionCase2() async throws -> () {
         let colA = ["sha256", "crc32"]
-        let colB = ["crc32", "sha256"]
         let validationMode = true
         var colBHeaders = Headers()
         // Add only sha256 header in response
@@ -209,7 +208,6 @@ class FlexibleChecksumsMiddlewareTests: XCTestCase {
 
     func testAlgorithmSelectionCase4() async throws -> () {
         let colA = ["crc32", "crc32c"]
-        let colB = ["crc32c", "crc32"]
         let validationMode = false
         var colBHeaders = Headers()
         // crc64 is not modeled in the service so no validation should be perforemd, but we shouldnt error