message: Remove --isolated from mb.py
  This option is not supported now.
  Cr-Commit-Position: refs/heads/main@{#35449}
diff: @@ -796,8 +796,6 @@ class MetaBuildWrapper(object):
  self.WriteJSON(
  {
  'args': [
  - '--isolated',
  - self.ToSrcRelPath('%s/%s.isolated' % (build_dir, target)),
  '--isolate',
  self.ToSrcRelPath('%s/%s.isolate' % (build_dir, target)),
  ],
  