now included upstream: sphinx-doc/sphinx@262240d

jquery and _.js will be removed in sphinx 6.0

contrary to the docs, this is not true by default

`result` has 6 elements, not 5. Doesn't matter at runtime, but might as well do it right

This reverts commit a097f33.

no longer necessary with fixed searchtools.js

Since sphinx no longer uses jQuery's `ready`, we'd be racing two `DOMContentLoaded`
events, with sphinx's listener always firing first and invoking the search scorer
without us having set a `pattern`.
Instead, we now initialize `pattern` when we need it instead of assuming that
it was set already.