Auto merge of #27303 - camelid:async-to-asynch, r=jdm

Use `asynch` instead of `r#async`

<!-- Please describe your changes on the following line: -->
This is a vestige of the transition from 2015 to 2018 edition Rust.
`async` was added as a keyword in 2018 edition Rust, so `cargo fix`
changed the variable name here to `r#async`.

---
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- [ ] `./mach build -d` does not report any errors
- [ ] `./mach test-tidy` does not report any errors
- [ ] These changes fix #___ (GitHub issue number if applicable)

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- [ ] There are tests for these changes OR
- [x] These changes do not require tests because this is just an internal name change

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components/script/script_module.rs

@@ -865,14 +865,14 @@ impl ModuleOwner {
                     }
                 };
 
-                let r#async = script
+                let asynch = script
                     .root()
                     .upcast::<Element>()
                     .has_attribute(&local_name!("async"));
 
-                if !r#async && (&*script.root()).get_parser_inserted() {
+                if !asynch && (&*script.root()).get_parser_inserted() {
                     document.deferred_script_loaded(&*script.root(), load);
-                } else if !r#async && !(&*script.root()).get_non_blocking() {
+                } else if !asynch && !(&*script.root()).get_non_blocking() {
                     document.asap_in_order_script_loaded(&*script.root(), load);
                 } else {
                     document.asap_script_loaded(&*script.root(), load);