GitLab::Users: Update options for e-mails API

GitLab/Users.pm

@@ -221,6 +221,9 @@ my $requests = {
         method      => "POST",
         path        => "/users/<uid>/emails",
         required    => [ qw!email! ],
+        optional    => [qw(
+            skip_confirmation
+        )],
     },
 
     self_delete_email => {