Output of `Encode`/`Decode` macros does not pass `trivial_numeric_casts` lint

[0x009922]

Versions:

• Rust: 1.87.0
• parity-scale-codec: 3.7.5

This code:

use parity_scale_codec::{Encode, Decode};

#[derive(Encode, Decode)]
pub enum Test {
    One,
    Two
}

Produces these errors:

error: trivial numeric cast: `usize` as `usize`
 --> src/lib.rs:5:5
  |
5 |     One,
  |     ^^^
  |
  = help: cast can be replaced by coercion; this might require a temporary variable
  = note: requested on the command line with `-D trivial-numeric-casts`

error: trivial numeric cast: `usize` as `usize`
 --> src/lib.rs:6:5
  |
6 |     Two
  |     ^^^
  |
  = help: cast can be replaced by coercion; this might require a temporary variable

error: trivial numeric cast: `usize` as `usize`
 --> src/lib.rs:5:5
  |
5 |     One,
  |     ^^^
  |
  = help: cast can be replaced by coercion; this might require a temporary variable

error: could not compile `parity-scale-trivial-num-casts-issue` (lib) due to 4 previous errors

Full reproduction: https://github.com/0x009922/parity-scale-trivial-num-casts-issue