fix typo

Co-authored-by: teor <teor@riseup.net>

Author: RalfJung

text/0000-unsafe-aliased.md

@@ -373,7 +373,7 @@ However, of course one could imagine alternatives:
   If we don't do this, we could consider removing `get` since since it seems too much like a foot-gun.
   But that makes shared references to `UnsafePinned` fairly pointless. Shared references to generators/futures are basically useless so it is unclear what the potential use-cases here are.
 
-- Instead of introducing a new type, we could say that `UnsafeCell` affects *both* shared and mutable references. That would lose some optimization potential on types like `&mut Cell<T>`, but would avoid the footgun of coercing an `&mut UnsafePinned<T>` to `&UnsafePinned<T>`. That said, so far the author is not aware of Miri detecting code that would run into this footgun (and Miri is [able to do detect such issues](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=aab417b535f7dbd266fbfe470ea208c7)).
+- Instead of introducing a new type, we could say that `UnsafeCell` affects *both* shared and mutable references. That would lose some optimization potential on types like `&mut Cell<T>`, but would avoid the footgun of coercing an `&mut UnsafePinned<T>` to `&UnsafePinned<T>`. That said, so far the author is not aware of Miri detecting code that would run into this footgun (and Miri is [able to detect such issues](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=aab417b535f7dbd266fbfe470ea208c7)).
 
 - We could entirely avoid all these problems by not having aliasing restrictions on mutable references.
   But that is completely against the direction Rust has had for 8 years now, and it would mean removing LLVM `noalias` annotations for mutable references (and likely boxes) entirely.