Clean up uploaded file after `test_media_handle_upload_sets_post_excerpt()`.

Props McGuive7.
Fixes #32534.

git-svn-id: https://develop.svn.wordpress.org/trunk@32794 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/tests/media.php

@@ -566,6 +566,9 @@ VIDEO;
 
 		$post = get_post( $post_id );
 
+		// Clean up.
+		wp_delete_attachment( $post_id );
+
 		$this->assertEquals( 'This is a comment. / Это комментарий. / Βλέπετε ένα σχόλιο.', $post->post_excerpt );
 	}