Add new run_lint_check_js.mjs

ESLint 8 removed CLIEngine. Therefore, we need to migrate away from
CLIEngine to the main ESLint class (which already exists in ESLint 7).
However, that class is based on promises, which means we can't use them
in a CommonJS context.

Therefore, introduce a new `.mjs` version that uses ES modules (which
can do as we are on a recent version of Node) and use the promise
versions. There are no other functional changes compared to the old
`.js` script.

The reason that we first have to add this file here, is that our CQ
directly refers to the `.js` version. That means we first land this CL,
we update our CQ configuration and only then can we remove the `.js`
file from our repository.

R=jacktfranklin@chromium.org

Bug: none
Change-Id: Iad3656931ae09eb7f9f23b3e6ad7d39c8a761a31
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/3268299
Reviewed-by: Jack Franklin <jacktfranklin@chromium.org>
Commit-Queue: Jack Franklin <jacktfranklin@chromium.org>
Auto-Submit: Tim van der Lippe <tvanderlippe@chromium.org>
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 1d6e66b..66db993 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -240,7 +240,7 @@
     results = [output_api.PresubmitNotifyResult('JS style check:')]
     lint_path = input_api.os_path.join(input_api.PresubmitLocalPath(),
                                        'scripts', 'test',
-                                       'run_lint_check_js.js')
+                                       'run_lint_check_js.mjs')
 
     front_end_directory = input_api.os_path.join(
         input_api.PresubmitLocalPath(), 'front_end')
@@ -273,7 +273,7 @@
         input_api.os_path.join(scripts_directory, 'test',
                                'run_lint_check_js.py'),
         input_api.os_path.join(scripts_directory, 'test',
-                               'run_lint_check_js.js'),
+                               'run_lint_check_js.mjs'),
         input_api.os_path.join(scripts_directory, '.eslintrc.js'),
         input_api.os_path.join(scripts_directory, 'eslint_rules'),
     ]