phpunit

Improve tests

Emit warning when a hook method such as setUp(), for example has a #[Test] attribute

Emit warning when both #[CoversNothing] and #[Covers*] (or #[Uses*]) are used on a test class for #6170

Emit warning when more than one of #[Small], #[Medium], or #[Large] is used on a test class for #6170

Simplify