infra/config: remove executable bit on dev/dev.star.

R=gbeaty

Change-Id: Ic567bb94e9505b5e5b3f5f6c7908652fc00da20e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2589318
Commit-Queue: Andrii Shyshkalov <tandrii@google.com>
Auto-Submit: Andrii Shyshkalov <tandrii@google.com>
Reviewed-by: Garrett Beaty <gbeaty@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836703}

infra/config/dev/dev.star

-#!/usr/bin/env lucicfg
 # Copyright 2020 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.