downgrade to kirby v3

kirby/src/Panel/Plugins.php

@@ -23,11 +23,15 @@ class Plugins
 {
 	/**
 	 * Cache of all collected plugin files
+	 *
+	 * @var array
 	 */
-	public array|null $files = null;
+	public $files;
 
 	/**
 	 * Collects and returns the plugin files for all plugins
+	 *
+	 * @return array
 	 */
 	public function files(): array
 	{
@@ -54,6 +58,8 @@ class Plugins
 	/**
 	 * Returns the last modification
 	 * of the collected plugin files
+	 *
+	 * @return int
 	 */
 	public function modified(): int
 	{
@@ -69,6 +75,9 @@ class Plugins
 
 	/**
 	 * Read the files from all plugins and concatenate them
+	 *
+	 * @param string $type
+	 * @return string
 	 */
 	public function read(string $type): string
 	{
@@ -131,6 +140,9 @@ class Plugins
 	/**
 	 * Absolute url to the cache file
 	 * This is used by the panel to link the plugins
+	 *
+	 * @param string $type
+	 * @return string
 	 */
 	public function url(string $type): string
 	{