Fixed opensearch double slash issue (#44137)

http://www.sphinx-doc.org/en/stable/config.html#confval-html_use_opensearch
"(without trailing slash)"

docs/docsite/rst/conf.py

@@ -183,7 +183,7 @@ html_copy_source = False
 # If true, an OpenSearch description file will be output, and all pages will
 # contain a <link> tag referring to it.  The value of this option must be the
 # base URL from which the finished HTML is served.
-html_use_opensearch = 'https://docs.ansible.com/ansible/latest/'
+html_use_opensearch = 'https://docs.ansible.com/ansible/latest'
 
 # If nonempty, this is the file name suffix for HTML files (e.g. ".xhtml").
 # html_file_suffix = ''