Fix typo in comment.

wutil-rs/src/notification.rs

@@ -49,7 +49,7 @@ pub type Action = unsafe extern "C" fn(observer: *mut c_void, notification: *con
 
 /// Wraps a type-erased pointer (which it does not own) and marks it as `Send`.
 ///
-/// The `Send`-ability of the wrapped pointer must be guaranteed code that
+/// The `Send`-ability of the wrapped pointer must be guaranteed by code that
 /// instantiates a `Sendable`.
 #[derive(Clone, Copy, Eq, PartialEq)]
 pub struct Sendable {