#14114: don't include copybutton.js in the htmlhelp output.

Doc/tools/sphinxext/layout.html

@@ -6,7 +6,7 @@
 {% endblock %}
 {% block extrahead %}
     <link rel="shortcut icon" type="image/png" href="{{ pathto('_static/py.png', 1) }}" />
-    <script type="text/javascript" src="{{ pathto('_static/copybutton.js', 1) }}"></script>
+    {% if not embedded %}<script type="text/javascript" src="{{ pathto('_static/copybutton.js', 1) }}"></script>{% endif %}
 {{ super() }}
 {% endblock %}
 {% block footer %}