fixed php8.2 deprecations on clarkson-core

Author: Floris-ll

clarkson-core.php

@@ -21,6 +21,13 @@
  */
 class Clarkson_Core {
 
+	/**
+	 * define $autoloader.
+	 *
+	 * @var Autoloader
+	 */
+	public $autoloader;
+
 	/**
 	 * Initializes all neccessery objects. Is automatically called on 'init'.
 	 *

wordpress-objects/Clarkson_Object.php

@@ -31,6 +31,13 @@ class Clarkson_Object implements \JsonSerializable {
 	 */
 	protected static $posts;
 
+	/**
+	 * define $_content.
+	 *
+	 * @var string
+	 */
+	public $_content;
+
 	/**
 	 * Clarkson_Object constructor.
 	 *
@@ -644,6 +651,7 @@ public function has_term( $term ) {
 	 *
 	 * We can't just return $this->_post, because these values will only return raw unfiltered data.
 	 */
+	#[\ReturnTypeWillChange]
 	public function jsonSerialize() {
 		$data['id']        = $this->get_id();
 		$data['link']      = $this->get_permalink();