chore: remove redundant words in comment

compiler/rustc_error_codes/src/error_codes/E0207.md

@@ -195,7 +195,7 @@ impl<'a> Contains for Foo {
 Please note that unconstrained lifetime parameters are not supported if they are
 being used by an associated type.
 
-In cases where the associated type's lifetime is meant to be tied to the the
+In cases where the associated type's lifetime is meant to be tied to the
 self type, and none of the methods on the trait need ownership or different
 mutability, then an option is to implement the trait on a borrowed type:
 

library/core/src/clone.rs

@@ -427,7 +427,7 @@ pub unsafe trait CloneToUninit {
     /// read or dropped, because even if it was previously valid, it may have been partially
     /// overwritten.
     ///
-    /// The caller may wish to to take care to deallocate the allocation pointed to by `dest`,
+    /// The caller may wish to take care to deallocate the allocation pointed to by `dest`,
     /// if applicable, to avoid a memory leak (but this is not a requirement).
     ///
     /// Implementors should avoid leaking values by, upon unwinding, dropping all component values

library/core/src/macros/mod.rs

@@ -1743,8 +1743,8 @@ pub(crate) mod builtin {
         /* compiler built-in */
     }
 
-    /// Provide a list of type aliases and other opaque-type-containing type definitions.
-    /// This list will be used in the body of the item it is applied to to define opaque
+    /// Provide a list of type aliases and other opaque-type-containing type definitions
+    /// to an item with a body. This list will be used in that body to define opaque
     /// types' hidden types.
     /// Can only be applied to things that have bodies.
     #[unstable(