[py3] Bump get_landmines to py3

Bug: v8:12581
Change-Id: I73d8248bd109c906aa0296b3b7bfc19ffd1c00ff
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3568447
Auto-Submit: Alexander Schulze <alexschulze@chromium.org>
Reviewed-by: Liviu Rau <liviurau@chromium.org>
Commit-Queue: Liviu Rau <liviurau@chromium.org>
Reviewed-by: Tamer Tas <tmrts@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79730}

tools/get_landmines.py

-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright 2014 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
@@ -8,9 +8,6 @@ This file emits the list of reasons why a particular build needs to be clobbered
 (or a list of 'landmines').
 """
 
-# for py2/py3 compatibility
-from __future__ import print_function
-
 import os
 import sys