Clippy: Tighten lints

- [x] Improve general infrastructure (#7482)
- [ ] Add clippy lints for better code quality (#7483)
- [ ] Add clippy lints for saver integer casts:
    ```
    cast_losless = "deny"
    cast_possible_truncation = "deny"
    cast_possible_wrap = "deny"
    cast_sign_loss = "deny"
    ```