fix(deprecated/*): remove instances (#4735)
Remove all instances constructing structures from `is_*` predicates, like for example:
```lean
instance subset.ring {S : set R} [is_subring S] : ring S :=
...
```
Co-Authored-By: Gabriel Ebner <gebner@gebner.org>
Co-authored-by: Gabriel Ebner <gebner@gebner.org>
