Update OffscreenCanvas support details (#32184)

Removed outdated information regarding OffscreenCanvas support.

manual/en/multiple-scenes.html

@@ -622,8 +622,7 @@ render the scene for this area, then copy the result to the area's canvas.</p>
 <p></p>
 <p>One other advantage to this solution is you could potentially use
 <a href="https://developer.mozilla.org/en-US/docs/Web/API/OffscreenCanvas"><code class="notranslate" translate="no">OffscreenCanvas</code></a>
-to render from a web worker and still use this technique. Unfortunately as of July 2020
-<code class="notranslate" translate="no">OffscreenCanvas</code> is only supported by Chrome.</p>
+to render from a web worker and still use this technique.
 
         </div>
       </div>
@@ -635,4 +634,4 @@ to render from a web worker and still use this technique. Unfortunately as of Ju
 
 
 
-</body></html>
+</body></html>