Fix grammar in Doc/tutorial/controlflow.rst (GH-21885) (#21923)

Automerge-Triggered-By: @csabella
(cherry picked from commit 0be7c21)

Co-authored-by: Denis Ovsienko <denis@ovsienko.info>

Doc/tutorial/controlflow.rst

@@ -658,7 +658,7 @@ Finally, consider this function definition which has a potential collision betwe
         return 'name' in kwds
 
 There is no possible call that will make it return ``True`` as the keyword ``'name'``
-will always to bind to the first parameter. For example::
+will always bind to the first parameter. For example::
 
     >>> foo(1, **{'name': 2})
     Traceback (most recent call last):