chore: remove repetitive words

Signed-off-by: cuishuang <imcusg@gmail.com>

library/core/src/mem/transmutability.rs

@@ -149,7 +149,7 @@ where
 #[derive(PartialEq, Eq, Clone, Copy, Debug)]
 pub struct Assume {
     /// When `false`, [`TransmuteFrom`] is not implemented for transmutations
-    /// that might violate the the alignment requirements of references; e.g.:
+    /// that might violate the alignment requirements of references; e.g.:
     ///
     #[cfg_attr(bootstrap, doc = "```rust,ignore not runnable on bootstrap")]
     #[cfg_attr(not(bootstrap), doc = "```compile_fail,E0277")]

library/std/src/sync/reentrant_lock.rs

@@ -136,7 +136,7 @@ cfg_if!(
             // match do we read out the actual TID.
             // Note also that we can use relaxed atomic operations here, because
             // we only ever read from the tid if `tls_addr` matches the current
-            // TLS address. In that case, either the the tid has been set by
+            // TLS address. In that case, either the tid has been set by
             // the current thread, or by a thread that has terminated before
             // the current thread was created. In either case, no further
             // synchronization is needed (as per <https://github.com/rust-lang/miri/issues/3450>)