Replace @covers and @coversDefaultClass annotations with #[CoversFunction()] and #[CoversClass()] attributes

Seemed to work ok for @coversDefaultClass, not sure @covers worked correctly. We probably also want to import the classes rather than using their FQCN in the attributes.

As spotted over in #3417066-120: Upgrade PHPUnit to 10, drop Symfony PHPUnit-bridge dependency → , we can't mix PHPUnit attributes and annotations, we will have to convert them all at once unfortunately. So we need to proceed by group of files and not by annotation.

I know this issue is "won't fix", but adding it here for anyone trying to use coverage attributes in PHPunit 11: the

#[CoverFunction(string 
$functionName)]

attribute is only available at the class level, not method level (WTF ?), per https://docs.phpunit.de/en/11.2/attributes.html#coversfunction so it cannot replace the @covers annotation.