Reland "[code-health] Migrate create_zip to python 3"

This is a reland of commit 2fae8a5
This is not run during any build and is unlikely to break any bot.

Original change's description:
> [code-health] Migrate create_zip to python 3
>
> * Update instructions to match.
> * Update bat file to use python 3 from PATH rather than a hardcoded
>   location.
>
> Bug: 1291048
> Change-Id: Ie84e9baa76da56900f2f2c6fc4eca3787d8dc360
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3564140
> Reviewed-by: Greg Thompson <grt@chromium.org>
> Commit-Queue: Fabrice de Gans <fdegans@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1049735}

Bug: 1364730
Change-Id: I7631d0b2a9e1895a5544063e574a980e4577421f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3923178
Commit-Queue: Greg Thompson <grt@chromium.org>
Auto-Submit: Fabrice de Gans <fdegans@chromium.org>
Reviewed-by: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1054829}

chrome/test/mini_installer/ZIP_README.txt

@@ -11,7 +11,7 @@ Running create_zip.py to distribute is the recommended way to distribute and
 run the tests. This method creates a batch file that will automatically
 set the paths.
 
-python chrome\test\mini_installer\create_zip.py ^
+vpython3 chrome\test\mini_installer\create_zip.py ^
   --output-path <ZIP_FILE_OUTPUT_PATH> ^
   --installer-path <CURRENT_INSTALLER_PATH> ^
   --previous-version-installer-path <PREVIOUS_INSTALLER_PATH> ^
@@ -34,7 +34,7 @@ since the default may be wrong.
 
 To run:
 
-1) Ensure the latest python 2.7 is installed and in your path
+1) Ensure the latest python 3 is installed and in your path
 2) Unzip zip file
 3) Open a command window in administrator mode
 4) Navigate to the unzip folder
@@ -49,4 +49,3 @@ if desired.
 
 The batch script will use Python's pip module to install pywin32 and psutil
 to reduce the amount of setup time is needed.
-

chrome/test/mini_installer/create_zip.py

@@ -1,3 +1,4 @@
+#!/usr/bin/env vpython3
 # Copyright 2018 The Chromium Authors
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.

chrome/test/mini_installer/zip_test_runner.bat

@@ -6,8 +6,9 @@ rem will be passed to run_mini_installer_tests.py. See
 rem chrome\test\mini_installer\run_mini_installer_tests.py for the args that
 rem can be passed.
 
-c:\Python27\python -m pip install --upgrade pip
-c:\Python27\Scripts\pip install psutil
-c:\Python27\Scripts\pip install pywin32
-c:\Python27\python chrome\test\mini_installer\run_mini_installer_tests.py {run_args} %*
+python3 -m pip install --upgrade pip
+python3 -m pip install psutil
+python3 -m pip install requests
+python3 -m pip install pypiwin32
+python3 chrome\test\mini_installer\run_mini_installer_tests.py {run_args} %*
 pause