Tests: Clean up attachments added during Tests_Ajax_wpAjaxSendAttachmentToEditor.

Tests in this class used to add attachments that weren't removed in the tear down class method. As such, following tests in other suites that ran after the ajax group were impacted. Specifically, when running `grunt precommit`, the test `WP_Test_REST_Attachments_Controller::test_sideload_scaled_unique_filename` in the multisite suite failed because it expected a filename `canola-scaled.jpg` and found `canola-scaled-1.jpg` instead.

Props mukesh27, mosescursor, mohamedahamed, afercia.
Fixes #65595.


git-svn-id: https://develop.svn.wordpress.org/trunk@62709 602fd350-edb4-49c9-b593-d223f7449a82

Author: afercia

tests/phpunit/tests/ajax/wpAjaxSendAttachmentToEditor.php

@@ -13,6 +13,15 @@
  */
 class Tests_Ajax_wpAjaxSendAttachmentToEditor extends WP_Ajax_UnitTestCase {
 
+	/**
+	 * Tear down the test fixture.
+	 */
+	public function tear_down() {
+		// Cleanup.
+		$this->remove_added_uploads();
+		parent::tear_down();
+	}
+
 	/**
 	 * Shared user ID for the tests.
 	 *