Auto merge of #18225 - jdm:unused-visitor-argument, r=emilio

Remove unused selector visitor argument.

The real win here is avoiding cloning the iterator when nobody actually uses it.

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] There are tests for these changes

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components/selectors/parser.rs

@@ -272,7 +272,7 @@ impl<Impl: SelectorImpl> SelectorMethods for Selector<Impl> {
         let mut current = self.iter();
         let mut combinator = None;
         loop {
-            if !visitor.visit_complex_selector(current.clone(), combinator) {
+            if !visitor.visit_complex_selector(combinator) {
                 return false;
             }