Fix some PHPstan warnings for PHP 8 support

example/includes/core.php

@@ -9,7 +9,7 @@ error_reporting(E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED);
 
 // Root directory path
 $script = null;
-if (defined('__FILE__') && constant('__FILE__')) {
+if (defined('__FILE__') && constant('__FILE__')) {  // @phpstan-ignore-line
   $script = __FILE__;
 }
 else {

skel/includes/core.php

@@ -8,7 +8,7 @@ error_reporting(E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED);
 
 // Root directory path
 $script = null;
-if (defined('__FILE__') && constant('__FILE__')) {
+if (defined('__FILE__') && constant('__FILE__')) {  // @phpstan-ignore-line
   $script = __FILE__;
 }
 else {

src/HookEvent.php

@@ -23,6 +23,11 @@ class HookEvent implements JsonSerializable {
     return null;
   }
 
+  /**
+   * Return data to serialize a HookEvent object as JSON
+   * @return array<string,mixed>
+   */
+  #[\ReturnTypeWillChange]
   public function jsonSerialize() {
     return array (
       'name' => $this -> name,

src/Session.php

@@ -21,6 +21,7 @@ class Session {
     // In CLI or Phpstan context, do not initialize
     if (
       php_sapi_name() == "cli"
+      // @phpstan-ignore-next-line
       || (defined('__PHPSTAN_RUNNING__') && constant('__PHPSTAN_RUNNING__'))
     )
       return;