chore: Fix docs typo (#5821)

# Description

## Problem\*

Resolves <!-- Link to GitHub Issue -->

## Summary\*

Cmp is not a trait, it should be Ord.

## Additional Context



## Documentation\*

Check one:
- [ ] No documentation needed.
- [x] Documentation included in this PR.
- [ ] **[For Experimental Features]** Documentation to be submitted in a
separate PR.

# PR Checklist\*

- [x] I have tested the changes locally.
- [x] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

docs/docs/noir/concepts/comptime.md

@@ -246,7 +246,7 @@ From the user's perspective it will look like this:
 
 ```rust
 // Example usage
-#[derive(Default, Eq, Cmp)]
+#[derive(Default, Eq, Ord)]
 struct MyStruct { my_field: u32 }
 ```