fix invalid access to thread-local access key ID
diff --git a/localstack/aws/handlers/auth.py b/localstack/aws/handlers/auth.py
index 47e36bef89198..ee471ab6a69c2 100644
--- a/localstack/aws/handlers/auth.py
+++ b/localstack/aws/handlers/auth.py
@@ -28,7 +28,9 @@ def __call__(self, chain: HandlerChain, context: RequestContext, response: Respo
         headers = context.request.headers
 
         if not headers.get("Authorization"):
-            headers["Authorization"] = aws_stack.mock_aws_request_headers(api)["Authorization"]
+            headers["Authorization"] = aws_stack.mock_aws_request_headers(
+                api, access_key="injectedaccesskey"
+            )["Authorization"]
 
 
 class AccountIdEnricher(Handler):
diff --git a/tests/integration/s3/test_s3_cors.py b/tests/integration/s3/test_s3_cors.py
index a55e921da9c43..728e02284772b 100644
--- a/tests/integration/s3/test_s3_cors.py
+++ b/tests/integration/s3/test_s3_cors.py
@@ -66,7 +66,6 @@ def _match(key: str, response: requests.Response):
 
 
 @pytest.mark.skipif(condition=LEGACY_S3_PROVIDER, reason="Tests are for new ASF provider")
-@pytest.mark.xfail(reason="xfail tests for now as they are failing")  # TODO: reactivate ASAP
 class TestS3Cors:
     @pytest.mark.aws_validated
     def test_cors_http_options_no_config(self, s3_bucket, snapshot, aws_client):

Recently, a CORS test continuously fails in CI, while it is not reproducible locally:
This PR aims at fixing this issue and unblocking the community pipeline.

This happens by disabling access to the threadlocal stored access key id before it is being set in the Authorization Header Injector.

Edit: It turns out that the flaky tests were caused by an invalid fallback to a thread-local. Details can be found in the great writeup of @dfangl: https://github.com/localstack/localstack/pull/8134#issuecomment-1512906567
This was an absolute great catch, thanks @dfangl and @bentsku for digging into this!