Feature: Improve default StreamSelectLoop to report any warnings for invalid streams. (#245 by @clue)

Feature: Improve performance of StreamSelectLoop when no timers are scheduled. (#246 by @clue)

Fix: Fix periodic timer with zero interval for ExtEvLoop and legacy ExtLibevLoop. (#243 by @lucasnetau)

Minor documentation improvements, update PHP version references. (#240, #248 and #250 by @SimonFrings, #241 by @dbu and #249 by @clue)

Improve test suite and test against PHP 8.1. (#238 by @WyriHaximus and #242 by @clue)