v1.9.0

• Feature: Add support for PHP 8.1 and PHP 8.2.
  (#44 by @SimonFrings and #51 by @WyriHaximus)

• Feature: Forward compatibility with upcoming Promise v3.
  (#33 by @WyriHaximus)

• Feature / Fix: Improve error reporting when custom error handler is used.
  (#49 by @clue)

• Feature: Avoid dependency on ext-filter.
  (#45 by @clue)

• Improve documentation and examples and update to use new reactphp/async package.
  (#50 by @nhedger, #53 by @dinooo13 and #47, #54 and #56 by @SimonFrings)

• Improve test suite and report failed assertions.
  (#48 by @SimonFrings and #55 by @clue)