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/ClonerTest.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Tests\Unit\Drivers\Gd;
+
+use Intervention\Image\Colors\Rgb\Color;
+use Intervention\Image\Drivers\Gd\Cloner;
+use Intervention\Image\Geometry\Rectangle;
+use Intervention\Image\Tests\BaseTestCase;
+
+final class ClonerTest extends BaseTestCase
+{
+    public function testClone(): void
+    {
+        $gd = imagecreatefromgif($this->getTestImagePath('gradient.gif'));
+        $clone = Cloner::clone($gd);
+
+        $this->assertEquals(16, imagesx($gd));
+        $this->assertEquals(16, imagesy($gd));
+        $this->assertEquals(16, imagesx($clone));
+        $this->assertEquals(16, imagesy($clone));
+
+        $this->assertEquals(
+            imagecolorsforindex($gd, imagecolorat($gd, 10, 10)),
+            imagecolorsforindex($clone, imagecolorat($clone, 10, 10))
+        );
+    }
+
+    public function testCloneEmpty(): void
+    {
+        $gd = imagecreatefromgif($this->getTestImagePath('gradient.gif'));
+        $clone = Cloner::cloneEmpty($gd, new Rectangle(12, 12), new Color(255, 0, 0, 0));
+
+        $this->assertEquals(16, imagesx($gd));
+        $this->assertEquals(16, imagesy($gd));
+        $this->assertEquals(12, imagesx($clone));
+        $this->assertEquals(12, imagesy($clone));
+
+        $this->assertEquals(
+            ['red' => 0, 'green' => 255, 'blue' => 2, 'alpha' => 0],
+            imagecolorsforindex($gd, imagecolorat($gd, 10, 10)),
+        );
+
+        $this->assertEquals(
+            ['red' => 255, 'green' => 0, 'blue' => 0, 'alpha' => 127],
+            imagecolorsforindex($clone, imagecolorat($clone, 10, 10))
+        );
+    }
+
+    public function testCLoneBlended(): void
+    {
+        $gd = imagecreatefromgif($this->getTestImagePath('gradient.gif'));
+        $clone = Cloner::cloneBlended($gd, new Color(255, 0, 255, 255));
+
+        $this->assertEquals(16, imagesx($gd));
+        $this->assertEquals(16, imagesy($gd));
+        $this->assertEquals(16, imagesx($clone));
+        $this->assertEquals(16, imagesy($clone));
+
+        $this->assertEquals(
+            ['red' => 0, 'green' => 0, 'blue' => 0, 'alpha' => 127],
+            imagecolorsforindex($gd, imagecolorat($gd, 1, 0)),
+        );
+
+        $this->assertEquals(
+            ['red' => 255, 'green' => 0, 'blue' => 255, 'alpha' => 0],
+            imagecolorsforindex($clone, imagecolorat($clone, 1, 0))
+        );
+    }
+}