asserthtml

This is a new version that's intended to be compatible with PHPUnit 10.
PHP and symfony versions have been changed to suit.

Breaking Changes

• Now requires PHP 8.1+
• Now requires PHPUnit 10
• Now requires Symfony 6

Other Changes

Switched from psalm to phpstan for internal static analysis.

• Updated the assertElementContains and assertElementNotContains methods so that the provided text is now tested against both the HTML and Plaintext content of the matched elements, whereas only the HTML was checked against before. Should not really be an issue unless you were specifically testing the the lack/existence of specific encoding (Related to #2).

• Fixed trait namespace.

Initial publish