chore(release): 4.18.0 [skip ci]

# [4.18.0](https://github.com/ezyang/htmlpurifier/compare/v4.17.0...v4.18.0) (2024-11-01)

### Bug Fixes

* Adjust Core.AllowHostnameUnderscore to consider that "_" is defined as Unreserved Characters in RFC 3986 ([#406](https://github.com/ezyang/htmlpurifier/issues/406)) ([d9fbef8](d9fbef8e27))
* Avoid a deprecated error when the attribute name is numeric and DirectLex is used ([#412](https://github.com/ezyang/htmlpurifier/issues/412)) ([f0fbf51](f0fbf51098))
* checking that node has property name ([#399](https://github.com/ezyang/htmlpurifier/issues/399)) ([9ca5a36](9ca5a3687b))
* Ignore conditional comments ([#401](https://github.com/ezyang/htmlpurifier/issues/401)) ([4828fdf](4828fdf45a))
* Support PHP 8.4 ([#396](https://github.com/ezyang/htmlpurifier/issues/396)) ([92da247](92da2473ff))
* undefined array key warning ([#419](https://github.com/ezyang/htmlpurifier/issues/419)) ([01be377](01be377f93))

### Features

* Add allowfullscreen attr for iframe ([#411](https://github.com/ezyang/htmlpurifier/issues/411)) ([70754a2](70754a2533))
* add directive for removing blank nodes ([#404](https://github.com/ezyang/htmlpurifier/issues/404)) ([c9d60c9](c9d60c96d7))
* Add support for CSS aspect-ratio ([#408](https://github.com/ezyang/htmlpurifier/issues/408)) ([93bee73](93bee73349))
* Allow universal CSS values for all properties ([#410](https://github.com/ezyang/htmlpurifier/issues/410)) ([9723267](972326785d))

Doxyfile

@@ -31,7 +31,7 @@ PROJECT_NAME           = HTMLPurifier
 # This could be handy for archiving the generated documentation or
 # if some version control system is used.
 
-PROJECT_NUMBER         = 4.17.0
+PROJECT_NUMBER         = 4.18.0
 
 # The OUTPUT_DIRECTORY tag is used to specify the (relative or absolute)
 # base path where the generated documentation will be put.