Drop explicit PRESUBMIT py2 test

R=gavinmak@google.com

Bug: 1376538
Change-Id: Ie5d1fbc2e7da1625f78016bb5d10e36d15ceb128
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4491463
Commit-Queue: Josip Sokcevic <sokcevic@chromium.org>
Reviewed-by: Gavin Mak <gavinmak@google.com>

tests/PRESUBMIT.py

@@ -1,27 +0,0 @@
-# Copyright (c) 2021 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-import sys
-
-PRESUBMIT_VERSION = '2.0.0'
-
-# This file can be removed once py2 presubmit is no longer supported. This is
-# an integration test to ensure py2 presubmit still works.
-
-
-def CheckPythonVersion(input_api, output_api):
-  # The tests here are assuming this is not defined, so raise an error
-  # if it is.
-  if 'USE_PYTHON3' in globals():
-    return [
-        output_api.PresubmitError(
-            'USE_PYTHON3 is defined; update the tests in //PRESUBMIT.py and '
-            '//tests/PRESUBMIT.py.')
-    ]
-  if sys.version_info.major != 2:
-    return [
-        output_api.PresubmitError(
-            'Did not use Python2 for //PRESUBMIT.py by default.')
-    ]
-  return []