Fix undefined name in test-only package (#31109)

* Fix undefined variable in test-only package

* Update e2e/aws/doc.go

Co-authored-by: Zac Bergquist <zac.bergquist@goteleport.com>

---------

Co-authored-by: Zac Bergquist <zac.bergquist@goteleport.com>

e2e/aws/doc.go

@@ -0,0 +1,16 @@
+// Copyright 2023 Gravitational, Inc
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package e2e contains end-to-end tests for Teleport's AWS integrations.
+package e2e

e2e/aws/fixtures_test.go

@@ -32,10 +32,8 @@ import (
 	"github.com/gravitational/teleport/lib/utils"
 )
 
-var (
-	// Username used for tests.
-	username string
-)
+// username is the name of the host user used for tests.
+var username string
 
 func init() {
 	me, err := user.Current()