PHPUnit 10 Migration (#1302)

* Bump PHPUnit dependencies

* Set return type of base TestCase methods

From the [PHPUnit 8 release notes][1], the `TestCase` methods below now declare a `void` return type:

- `setUpBeforeClass()`
- `setUp()`
- `assertPreConditions()`
- `assertPostConditions()`
- `tearDown()`
- `tearDownAfterClass()`
- `onNotSuccessfulTest()`

[1]: https://phpunit.de/announcements/phpunit-8.html

* Ignore PHPUnit cache folder

* Adopt PHP attributes in test classes

* Declare data providers as `static`

* Add return types to test methods

* Define test classes as `final`

* Migrate phpunit.xml to phpunit 10

* Correct phpunit attribute class name

* Rename base test class

* Restructure test folders

* Fix test image paths

* Only set rules for php files in .editorconfig

* Remove php unit flag in local test env

---------

Co-authored-by: Shift <shift@laravelshift.com>

tests/Unit/Drivers/Gd/Modifiers/ContainModifierTest.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Tests\Unit\Drivers\Gd\Modifiers;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\RequiresPhpExtension;
+use Intervention\Image\Modifiers\ContainModifier;
+use Intervention\Image\Tests\BaseTestCase;
+use Intervention\Image\Tests\Traits\CanCreateGdTestImage;
+
+#[RequiresPhpExtension('gd')]
+#[CoversClass(\Intervention\Image\Modifiers\ContainModifier::class)]
+#[CoversClass(\Intervention\Image\Drivers\Gd\Modifiers\ContainModifier::class)]
+final class ContainModifierTest extends BaseTestCase
+{
+    use CanCreateGdTestImage;
+
+    public function testModify(): void
+    {
+        $image = $this->readTestImage('blocks.png');
+        $this->assertEquals(640, $image->width());
+        $this->assertEquals(480, $image->height());
+        $image->modify(new ContainModifier(200, 100, 'ff0'));
+        $this->assertEquals(200, $image->width());
+        $this->assertEquals(100, $image->height());
+        $this->assertColor(255, 255, 0, 255, $image->pickColor(0, 0));
+        $this->assertTransparency($image->pickColor(140, 10));
+        $this->assertColor(255, 255, 0, 255, $image->pickColor(175, 10));
+    }
+}