chore: update protocol tests

Author: kuhe

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AwsProtocolUtils.java

@@ -312,6 +312,11 @@ private static boolean filterProtocolTests(
             return true;
         }
 
+        // TODO: Remove when upstream tests update to serialize empty headers.
+        if (testCase.getId().contains("NullAndEmptyHeaders")) {
+            return true;
+        }
+
         if (testCase.getTags().contains("defaults")) {
             return true;
         }

private/aws-protocoltests-restjson/test/functional/restjson1.spec.ts

@@ -6719,7 +6719,7 @@ it("RestJsonNoInputAndOutputNoPayload:Response", async () => {
 /**
  * Do not send null values, empty strings, or empty lists over the wire in headers
  */
-it("RestJsonNullAndEmptyHeaders:Request", async () => {
+it.skip("RestJsonNullAndEmptyHeaders:Request", async () => {
   const client = new RestJsonProtocolClient({
     ...clientParams,
     requestHandler: new RequestSerializationTestHandler(),

private/aws-protocoltests-restxml/test/functional/restxml.spec.ts

@@ -3735,7 +3735,7 @@ it("NoInputAndOutput:Response", async () => {
 /**
  * Do not send null values, empty strings, or empty lists over the wire in headers
  */
-it("NullAndEmptyHeaders:Request", async () => {
+it.skip("NullAndEmptyHeaders:Request", async () => {
   const client = new RestXmlProtocolClient({
     ...clientParams,
     requestHandler: new RequestSerializationTestHandler(),

private/aws-restjson-server/test/functional/restjson1.spec.ts

@@ -27857,7 +27857,7 @@ it("RestJsonNoInputAndOutputWithJson:ServerResponse", async () => {
 /**
  * Do not send null or empty headers
  */
-it("RestJsonNullAndEmptyHeaders:ServerResponse", async () => {
+it.skip("RestJsonNullAndEmptyHeaders:ServerResponse", async () => {
   class TestService implements Partial<RestJsonService<{}>> {
     NullAndEmptyHeadersServer(input: any, ctx: {}): Promise<NullAndEmptyHeadersServerServerOutput> {
       const response = {