bpo-40730: Remove redundant 'to' (GH-20316) (GH-20318)

@ericvsmith I guess it is correct to merge it into master and not 3.9 directly?

Automerge-Triggered-By: @ericvsmith
(cherry picked from commit 30d5a73)

Co-authored-by: Florian Dahlitz <[email protected]>

Co-authored-by: Florian Dahlitz <[email protected]>

Author: miss-islington

Doc/whatsnew/3.9.rst

@@ -605,7 +605,7 @@ Optimizations
 
      sums = [s for s in [0] for x in data for s in [s + x]]
 
-  Unlike to the ``:=`` operator this idiom does not leak a variable to the
+  Unlike the ``:=`` operator this idiom does not leak a variable to the
   outer scope.
 
   (Contributed by Serhiy Storchaka in :issue:`32856`.)