How do you do that after destroying Stone with a golden pick, you cancel the task of renewing?

How do you do that after destroying Stone with a golden pick, you cancel the task of renewing?

PHP:

<?php
public function onBreak(BlockBreakEvent $event){
  $blok = $event->getBlock();
  $gracz = $event->getPlayer();
  $y = $blok->getFloorY();
  $x = $blok->getFloorX();
  $z = $blok->getFloorZ();
    if($blok->getId() == 1){
   $task = new Task($this, $event->getBlock()->getFloorX(), $event->getBlock()->getFloorY(), $event->getBlock()->getFloorZ());
       $this->getServer()->getScheduler()->scheduleDelayedTask($task, 30);
        }
     }
}

//Task.php
<?php

namespace StoneFarm;

use pocketmine\block\Block;
use pocketmine\block\Air;
use pocketmine\block\Stone;
use pocketmine\math\Vector3;
use pocketmine\scheduler\PluginTask;

class Task extends PluginTask{

    private $z;
    private $y;
    private $x;
private $gracz;
    
    public function  __construct($gracz, $x, $y, $z){
parent::__construct($gracz);
    $this->x = $x;
$this->y = $y;
$this->z = $z;
$this->gracz = $gracz;
    }
    
    

public function onRun($currentTick){
$level = $this->gracz->getServer()->getLevelByName("world");
if($level->getBlock(new Vector3($this->x, $this->y, $this->z))->getId() == 0) { 
       $level->setBlock(new Vector3($this->x, $this->y, $this->z), new Stone());
    }
}
}