Fix return type of SessionHandler::gc()

Relates to GH-7006

Author: kocsismate

ext/session/session.stub.php

@@ -80,7 +80,7 @@ public function write(string $id, string $data);
     /** @return bool */
     public function destroy(string $id);
 
-    /** @return int|bool */
+    /** @return int|false */
     public function gc(int $max_lifetime);
 }
 
@@ -116,7 +116,7 @@ public function write(string $id, string $data) {}
     /** @return bool */
     public function destroy(string $id) {}
 
-    /** @return int|bool */
+    /** @return int|false */
     public function gc(int $max_lifetime) {}
 
     /** @return string */

ext/session/session_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 88f428841bc3e12b949a3308d60eae80d87e563a */
+ * Stub hash: 4221e895bdb0c3e903b7688f79e2863fc0788cee */
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_session_name, 0, 0, MAY_BE_STRING|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, name, IS_STRING, 1, "null")