Fix typo with extra "the"

(HT: @tommystanton)

doc/Language/functions.pod6

@@ -728,7 +728,7 @@ say LoggedVersion.new('1.0.2');
 =end code
 
 If you need to make multiple calls to the wrapped code or to gain a reference to
-it, such as for performing introspection on the it, you can use C<nextcallee>.
+it, such as performing introspection it, you can use C<nextcallee>.
 
 =begin code
 sub power-it($x) { $x * $x }