Remove searchbox id from form (fixes python#117)

Author: septatrix

python_docs_theme/layout.html

@@ -103,7 +103,7 @@ <h3>{{ _('Navigation') }}</h3>
             </a>
             <span class="version_switcher_placeholder"></span>
             {%- if pagename != "search" and builder != "singlehtml" %}
-            <form id="searchbox" role="search" class="search" action="{{ pathto('search') }}" method="get">
+            <form role="search" class="search" action="{{ pathto('search') }}" method="get">
                 <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" class="search-icon">
                     <path fill-rule="nonzero" fill="currentColor" d="M15.5 14h-.79l-.28-.27a6.5 6.5 0 001.48-5.34c-.47-2.78-2.79-5-5.59-5.34a6.505 6.505 0 00-7.27 7.27c.34 2.8 2.56 5.12 5.34 5.59a6.5 6.5 0 005.34-1.48l.27.28v.79l4.25 4.25c.41.41 1.08.41 1.49 0 .41-.41.41-1.08 0-1.49L15.5 14zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z"></path>
                 </svg>