chore: remove repetitive words

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

Author: cuishuang

library/core/src/pin.rs

@@ -733,7 +733,7 @@
 //! sensitivity, it will need to be structurally pinned.
 //!
 //! A useful test is if [`unsafe`] code that consumes <code>[Pin]\<[&mut Struct][&mut]></code>
-//! also needs to take note of the address of the field itself, it may be evidence that that field
+//! also needs to take note of the address of the field itself, it may be evidence that field
 //! is structurally pinned. Unfortunately, there are no hard-and-fast rules.
 //!
 //! ### Choosing pinning *not to be* structural for `field`...

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>)