Fix the python call to sys.executable, and sort imports

Change-Id: I948291e0835c79445108f215e55885fdb2c01052
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2560592
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71423}