dompurify 2.0.4

Another mXSS variation was spotted by @masatokinugawa and got addressed and fixed in this release.

The fixes were reviewed and no new bypasses could be spotted at the moment. Thanks, @masatokinugawa :bowing_man: :bowing_woman:!

The sanitization logic for this kind of mXSS was changed to be less aggressive and still be able to spot all recent mXSS variations we know about right now - while also avoiding risky string matching.

Prayers and thoughts that this was the final variation. But better be on the lookout for more releases soon.