remove lint step. It wasn't running on all files on cirrus therefore it is failing on some PRs on LUCI

Example Linux Web Engine run: https://chromium-swarm.appspot.com/task?id=4d85ed685fd14a10
Example Linux Host Engine run: https://chromium-swarm.appspot.com/task?id=4d85ed855185ef10

Change-Id: Ib948f84c4a2ef9a9e9ad1029c743cbdf125b94b0
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/4460
Reviewed-by: Christopher Fujino <fujino@google.com>
Reviewed-by: Godofredo Contreras <godofredoc@google.com>
Commit-Queue: Nurhan Turgut <nurhan@google.com>