Merge #732

732: Fix clippy error in webhook due to rust 1.91.0 r=curquiza a=kumarUjjawal

# Pull Request

## Related issue
Fixes #731 

## What does this PR do?
- Fix clippy issue introduced in webhook module.

## PR checklist
Please check if your PR fulfills the following requirements:
- [x] Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
- [x] Have you read the contributing guidelines?
- [x] Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!


<!-- This is an auto-generated comment: release notes by coderabbit.ai -->

## Summary by CodeRabbit

* **Refactor**
  * Optimized internal implementation of default value handling to align with Rust best practices.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Co-authored-by: Kumar Ujjawal <[email protected]>

Author: meili-bors[bot]

src/webhooks.rs

@@ -66,19 +66,14 @@ impl WebhookCreate {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
 enum HeadersUpdate {
+    #[default]
     NotSet,
     Reset,
     Set(BTreeMap<String, Option<String>>),
 }
 
-impl Default for HeadersUpdate {
-    fn default() -> Self {
-        Self::NotSet
-    }
-}
-
 /// Payload used to update or delete settings of an existing webhook.
 #[derive(Debug, Clone, Default, PartialEq, Eq)]
 pub struct WebhookUpdate {