<?php if($current_page + 1 > $total_pages){?>
    <button class="next" onclick="window.location.href = '/jobs/page/<?=$current_page?>';">Далее</button>
<?php } 
else {
?>
    <button class="next" onclick="window.location.href = '/jobs/page/<?=$current_page + 1?>';">Далее</button>
<?php }
?>