Dogfood ty on the `scripts` directory (#21617)
## Summary
This PR sets up CI jobs to run ty from the `main` branch on the files
and subdirectories in our `scripts` directory
## Test Plan
Both these commands pass for me locally:
- `uv run --project=./scripts cargo run -p ty check --project=./scripts`
- `uv run --project=./scripts/ty_benchmark cargo run -p ty check
--project=./scripts/ty_benchmark`
