Editorial: remove some copypasta

Editing DOM and HTML at the same time is not advisable.

Author: annevk

source

@@ -99870,7 +99870,7 @@ interface <dfn interface>NotRestoredReasons</dfn> {
      <dd>true</dd>
 
      <dt><span data-x="document-custom-element-registry">custom element registry</span></dt>
-     <dd>A new {{CustomElementRegistry}} object.</dd>
+     <dd>A new <code>CustomElementRegistry</code> object.</dd>
     </dl>
    </li>
 
@@ -106433,7 +106433,7 @@ location.href = '#foo';</code></pre>
      <dd>true</dd>
 
      <dt><span data-x="document-custom-element-registry">custom element registry</span></dt>
-     <dd>A new {{CustomElementRegistry}} object.</dd>
+     <dd>A new <code>CustomElementRegistry</code> object.</dd>
     </dl>
    </li>