fix for `omit_local_variable_types` can leave unused imports

[pq]

Any fix that removes a type reference (or API call) might leave dead imports.

We might consider removing the (newly) unneeded import when performing the fix.

This is especially impacting in applying bulk fixes.

Related to: #43886.

[srawlins]

With so many lints and so many fixes (I love it), I think a more general solution might be needed.

1. Would it be too crazy to repeatedly fix until stability is reached? In round one, a type might be removed; in round two an import might be removed; in round three a pub dependency might be removed.
2. Are there not too many rules that a fix might trigger? unused_xyz, unnecessary_xyz? A second round could be triggered that just fixes those.

[bwilkerson]

I had forgotten about (or never known about) this issue. The dart fix tool has already been updated to do just the kind of iteration you suggested. I'm going to close this issue with the assumption that there isn't any additional work required.

[srawlins]

That's excellent, I had no idea!