Test_WP_Widget_Media::test_constructor(): remove use of assertArraySu…

…bset()

The `assertArraySubset()` method has been deprecated in PHPUnit 8 and removed in PHPUnit 9.

Replacing the assertions with looping through the array and testing both the key and the value individually.

Refs:
* https://github.com/sebastianbergmann/phpunit/blob/8.0.6/ChangeLog-8.0.md#800---2019-02-01
* sebastianbergmann/phpunit#3494

tests/phpunit/tests/widgets/media-widget.php

@@ -95,10 +95,14 @@ function test_constructor() {
 		$this->assertEquals( $id_base, $widget->id_base );
 		$this->assertEquals( $name, $widget->name );
 
-		// Method assertArraySubset doesn't exist in phpunit versions compatible with PHP 5.2.
-		if ( method_exists( $this, 'assertArraySubset' ) ) {
-			$this->assertArraySubset( $widget_options, $widget->widget_options );
-			$this->assertArraySubset( $control_options, $widget->control_options );
+		foreach ( $widget_options as $key => $value ) {
+			$this->assertArrayHasKey( $key, $widget->widget_options );
+			$this->assertSame( $value, $widget->widget_options[ $key ] );
+		}
+
+		foreach ( $control_options as $key => $value ) {
+			$this->assertArrayHasKey( $key, $widget->control_options );
+			$this->assertSame( $value, $widget->control_options[ $key ] );
 		}
 	}