Fix <link>.workerType IDL

9c7da49 removed the idea of using
enumerations in the IDL to case-sensitively reflect properties, but
forgot to switch <link>'s workerType attribute to DOMString.

source

@@ -12928,7 +12928,7 @@ interface <dfn>HTMLLinkElement</dfn> : <span>HTMLElement</span> {
   [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-link-sizes">sizes</span>;
   [<span>CEReactions</span>] attribute DOMString <span data-x="dom-link-referrerPolicy">referrerPolicy</span>;
   [<span>CEReactions</span>] attribute USVString <span data-x="dom-link-scope">scope</span>;
-  [<span>CEReactions</span>] attribute <span>WorkerType</span> <span data-x="dom-link-workertype">workerType</span>;
+  [<span>CEReactions</span>] attribute DOMString <span data-x="dom-link-workertype">workerType</span>;
   [<span>CEReactions</span>] attribute boolean <span data-x="dom-link-useCache">useCache</span>;
 };
 <span>HTMLLinkElement</span> implements <span>LinkStyle</span>;</pre>