Remove extraneous .unique call

Author: bduggan

doc/Type/Hash.pod6

@@ -509,13 +509,13 @@ initialization very useful ways. Take for instance the case of an inverted
 index:
 
     my %wc = 'hash' => 323, 'pair' => 322, 'pipe' => 323;
-    (my %inv).push: %wc.invert.unique;
+    (my %inv).push: %wc.invert;
     say %inv;                           # OUTPUT: «{322 => pair, 323 => [pipe hash]}␤»
 
 Note that such a initialization could also be written as
 
     my %wc = 'hash' => 323, 'pair' => 322, 'pipe' => 323;
-    my %inv .= push: %wc.invert.unique;
+    my %inv .= push: %wc.invert;
 
 B<Note:> Compared to L«C<append>|/routine/append», C<push> will add the given
 value as is, whereas C<append> will L«C<slip>|/routine/slip» it in: