This commit updates the parser logic to continue to try to match an end
tag to an unclosed open tag on the stack. Previously, it would only
push an error to the list and stop looking at unclosed elements.
For example, the invalid HTML of `<li><div></li>`, has an unclosed
element stack of [`li`, `div`] when it encounters the close `li` tag.
We compare against the previously unclosed tag `div` and see that this is
unexpected. Instead of simply giving up here, we continue to move up the
unclosed tags until we find a match (if there is one).
PR Close#42554