5.2 release notes - fix code type

- We usually use `javascript` not `js`

docs/releases/5.2.md

@@ -368,7 +368,7 @@ This behaviour has now moved to a Stimulus controller and leverages DOM events i
 
 You can implement roughly the equivalent functionality with this JavaScript function, however, this will not be guaranteed to work in future releases.
 
-```js
+```javascript
 window.updateFooterSaveWarning = (formDirty, commentsDirty) => {
   if (!formDirty && !commentsDirty) {
     document.dispatchEvent(new CustomEvent('w-unsaved:clear'));