Tenta este import.

use clap::{Parser, arg, command};

E veja se esta usando a versao clap a partir da 3.

Eu não testei, estou longe do PC.

Olá. O erro ainda aparece:

error: cannot find attribute `command` in this scope
 --> src/main.rs:5:3
  |
5 | #[command(version, about, long_about = None)]
  |   ^^^^^^^
  |
note: `command` is imported here, but it is a function-like macro
 --> src/main.rs:1:25
  |
1 | use clap::{Parser, arg, command};
  |                         ^^^^^^^

error: cannot find attribute `arg` in this scope
 --> src/main.rs:8:7
  |
8 |     #[arg(short, long)]
  |       ^^^
  |
note: `arg` is imported here, but it is a function-like macro
 --> src/main.rs:1:20
  |
1 | use clap::{Parser, arg, command};
  |                    ^^^

error: cannot find attribute `arg` in this scope
  --> src/main.rs:12:7
   |
12 |     #[arg(short, long, default_value_t = 1)]
   |       ^^^
   |
note: `arg` is imported here, but it is a function-like macro
  --> src/main.rs:1:20
   |
1  | use clap::{Parser, arg, command};
   |                    ^^^

error: could not compile `proj_11_05` (bin "proj_11_05") due to 3 previous errors

A versão é acima da 3.