Description

The #[derive(OpenApi)] macro generates code that triggers a clippy warning for needless_for_each, which cannot be suppressed at the derive site and requires a module-level #![allow(clippy::needless_for_each)] to silence.

Steps to Reproduce:

1. Create a struct with #[derive(OpenApi)]
2. Run cargo clippy with pedantic lints enabled

Example Code:

use utoipa::OpenApi;

#[derive(OpenApi)]
#[openapi(
    paths(),
    components(),
    tags((name = "api", description = "API")),
    info(title = "Test API", version = "1.0.0")
)]
struct ApiDoc;

Expected Behavior:
No clippy warnings should be generated from derive macro code.

Actual Behavior:

warning: needless use of `for_each`
  --> src/main.rs:XX:XX
   |
XX | #[derive(OpenApi)]
   |          ^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_for_each
   = note: this warning originates in the derive macro `OpenApi`

Environment:

utoipa version: 5.4.0
Rust version: nightly (rustc 1.90.0-nightly (28f1c8079 2025-06-24))
Clippy: nightly (rustc 1.90.0-nightly (28f1c8079 2025-06-24))

Workaround:
Currently requires adding #![allow(clippy::needless_for_each)] at the module level.

Suggested Fix:
Use a for loop instead of for_each where appropriate