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.

---
- [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/style/stylist.rs

@@ -1652,7 +1652,6 @@ impl<'a> SelectorVisitor for StylistSelectorVisitor<'a> {
 
     fn visit_complex_selector(
         &mut self,
-        _: SelectorIter<SelectorImpl>,
         combinator: Option<Combinator>
     ) -> bool {
         self.needs_revalidation =