Auto-upgrader should recommend changing HashSet to SequencedSet, not SortedSet

[ge0ffrey]

To avoid triggering #2273
the OpenRewrite recipe shouldn't recommend SortedSet, but SequencedSet instead.

I was previously just using HashSets. After the upgrade, the text said I needed to use SortedSet instead to run reproducibly.
It appeared on the console when I ran the version that used HashSets after upgrading.