Add sphinx_highlight.js to the search page (needed since sphinx 5.2.0).
<script src="{{ pathto('_static/doctools.js', 1) }}"></script>
<script src="{{ pathto('_static/language_data.js', 1) }}"></script>
<script src="{{ pathto('_static/searchtools.js', 1) }}"></script>
+ <script src="{{ pathto('_static/sphinx_highlight.js', 1) }}"></script>
{% endblock %}
