perf: skip local instance check for the new argument in `MatcherApp.addArg`

`updateAlts` introduced the new alternative argument with `forallBoundedTelescope`, which checks whether its type is a class. The argument is only abstracted, so the check is skipped.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2 files changed