[fix] Removes `/>` ending tags for void HTML elements

Removes ``/>`` ending tags for void elements [1] and replaces them with ``>``.
Part of the larger cleanup to cleanup invalid HTML throughout the codebase [2].

[1] https://html.spec.whatwg.org/multipage/syntax.html#void-elements
[2] https://github.com/searxng/searxng/issues/3793

searx/engines/btdigg.py

@@ -54,7 +54,6 @@ def response(resp):
 
         excerpt = result.xpath('.//div[@class="torrent_excerpt"]')[0]
         content = html.tostring(excerpt, encoding='unicode', method='text', with_tail=False)
-        # it is better to emit <br/> instead of |, but html tags are verboten
         content = content.strip().replace('\n', ' | ')
         content = ' '.join(content.split())