Simplify `LinterResult`, avoid cloning `ParseError` (#11903)
## Summary
Follow-up to #11902
This PR simplifies the `LinterResult` struct by avoiding the generic and
not store the `ParseError`.
This is possible because the callers already have access to the
`ParseError` via the `Parsed` output. This also means that we can
simplify the return type of `check_path` and avoid the generic `T` on
`LinterResult`.
## Test Plan
`cargo insta test`
