[nnbd_migration] add a dep on package:lints
[nnbd_migration] add a dep on package:lints

Change-Id: I6719e140c8a3ec56fe90fbb3c67ca9548a3724a5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/241681
Reviewed-by: Samuel Rawlins <5cf2cac5eec2ad6d0eb2b0f4ff6af9a590ce2bf6@google.com>
Reviewed-by: Paul Berry <72d414e3a99fb120308437779d51667bcc0984eb@google.com>
Commit-Queue: Devon Carew <e996497f4f2225f0ee7a9f4d1696ee710b488b66@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk