[php-src] PR #25087: Fix GH-25086: Io\Poll kqueue backend leaks memory on every modifyEvents()

Pull Request: https://github.com/php/php-src/pull/25087 Author: lazerg kqueue_backend_modify() only deleted the filters that weren't in the new event set, so when it got no successful deletes it assumed the fd had no filters before and added the full new set to filter_count. Going from Read to Read+Write therefore counted the already registered read filter again. get_suitable_max_events() returns filter_count, so every wait() grew the struct kevent buffer by one entry per modify. It now deletes both filters first, which gives the real number of registered filters, and then adds the requested ones. Fixes #25086