test: Use PHPUnit attributes for Kirby\Template

[distantnative]

Description

Summary of changes

• Use CoversClass and DataProvider PHPUnit PHP attributes instead of DocBlock annotations in the Kirby\Template package

Reasoning

Switching over package by package (or smaller units) to see how the code coverage is affected.

Additional context

Put this for the 5.1.0 milestone to not further add to the list of the 5.0.0 milestone as we want to close this very soon.

The changes were created automatically with Rector:

<?php

declare(strict_types = 1);

use Rector\Config\RectorConfig;
use Rector\PHPUnit\AnnotationsToAttributes\Rector\Class_\CoversAnnotationWithValueToAttributeRector;
use Rector\PHPUnit\AnnotationsToAttributes\Rector\ClassMethod\DataProviderAnnotationToAttributeRector;
use Rector\TypeDeclaration\Rector\ClassMethod\AddVoidReturnTypeWhereNoReturnRector;

return RectorConfig::configure()
	->withPaths([
		__DIR__ . '/tests/Template',
	])
	->withRules([
		CoversAnnotationWithValueToAttributeRector::class,
		DataProviderAnnotationToAttributeRector::class,
		AddVoidReturnTypeWhereNoReturnRector::class
	])
	->withImportNames();

Ready?

• In-code documentation (wherever needed)
• Unit tests for fixed bug/feature
• Tests and CI checks all pass