8.2
[CssSelector] Various fixes and hardenings
Add PR template and auto-close PR on subtree split repositories
Added missing files .gitignore
[CssSelector] Add `:has()` support
[CssSelector] Add LRU cache to CssSelectorConverter
Update license years (last time)
Add call to backers in README files
Bump to php >= 8.4.1
Update XSD references in phpunit.xml.dist files