Editorial: remove outdated use of "EnvironmentRecord"

See tc39/ecma262#1697 for context. Also adjust the style as per Web IDL.

source

@@ -2752,7 +2752,6 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li><dfn data-x-href="https://tc39.es/ecma262/#execution-context-stack">JavaScript execution context stack</dfn></li>
      <li><dfn data-x-href="https://tc39.es/ecma262/#sec-code-realms">JavaScript realm</dfn></li>
      <li><dfn data-x-href="https://tc39.es/ecma262/#sec-jobcallback-records">JobCallback Record</dfn></li>
-     <li><dfn data-x-href="https://tc39.es/ecma262/#sec-lexical-environments">EnvironmentRecord</dfn></li>
      <li><dfn data-x-href="https://tc39.es/ecma262/#sec-built-in-function-objects">NewTarget</dfn></li>
      <li><dfn data-x-href="https://tc39.es/ecma262/#running-execution-context">running JavaScript execution context</dfn></li>
      <li><dfn data-x-href="https://tc39.es/ecma262/#surrounding-agent">surrounding agent</dfn></li>
@@ -81525,9 +81524,8 @@ dictionary <dfn dictionary>WindowPostMessageOptions</dfn> : <span>StructuredSeri
 
   <p>The <dfn attribute for="Window"><code data-x="dom-window">window</code></dfn>, <dfn attribute
   for="Window"><code data-x="dom-frames">frames</code></dfn>, and <dfn attribute for="Window"><code
-  data-x="dom-self">self</code></dfn> attributes' getters must return this <code>Window</code>
-  object's <span data-x="concept-relevant-realm">relevant Realm</span>.[[GlobalEnv]]'s
-  <span>EnvironmentRecord</span>'s [[GlobalThisValue]].</p>
+  data-x="dom-self">self</code></dfn> getter steps are to return <span>this</span>'s <span
+  data-x="concept-relevant-realm">relevant Realm</span>.[[GlobalEnv]].[[GlobalThisValue]].</p>
 
   <p>The <dfn attribute for="Window"><code data-x="dom-document">document</code></dfn> IDL
   attribute, on getting, must return this <code>Window</code> object's <span