feat: Support PHPUnit 11

[michalbundyra]

No description provided.

[herndlm]

fyi I can upgrade to and use PHPUnit 11 now with a green pipeline in a project where we are using both php-mock/php-mock-mockery and php-mock/php-mock-phpunit 🎉

it's not an issue per se, but I noticed that unfortunately there are deprecations coming from inside this lib, presumably both https://github.com/php-mock/php-mock-phpunit/blob/2.10.0/classes/PHPMock.php#L69 and https://github.com/php-mock/php-mock-phpunit/blob/2.10.0/classes/PHPMock.php#L72

• MockBuilder::addMethods() is deprecated and will be removed in PHPUnit 12. No replacement is/will be provided.

• MockBuilder::getMockForAbstractClass() is deprecated and will be removed in PHPUnit 12. No replacement is/will be provided.

Again, I don't think these are issues, but maybe we can avoid them somehow before people create issues here.