servo: Merge #8482 - Remove unnecessary '*_mut' methods (from frewsxcv:no-mut); r=Ms2ger

Source-Repo: https://github.com/servo/servo
Source-Revision: 448c7fb2e6758ca069104820fd5ac6b94725a1d5

servo/components/script/page.rs

@@ -79,8 +79,8 @@ impl Page {
     pub fn remove(&self, id: PipelineId) -> Option<Rc<Page>> {
         let remove_idx = {
             self.children
-                .borrow_mut()
-                .iter_mut()
+                .borrow()
+                .iter()
                 .position(|page_tree| page_tree.id == id)
         };
         match remove_idx {