Composer, Ubuntu and php version

So, last week I did install a new OC v2 on a Ubuntu 20.4 staging server using the Deploy plugin. All was fine.
I am now pushing a new version of my plugin and want to update the staging server with the command
php artisan october:update

and receive this error

Composer detected issues in your platform:

Your Composer dependencies require a PHP version ">= 7.4.0". You are running 7.3.28-1+ubuntu16.04.1+deb.sury.org+1.

PHP Fatal error:  Composer detected issues in your platform: Your Composer dependencies require a PHP version ">= 7.4.0". You are running 7.3.28-1+ubuntu16.04.1+deb.sury.org+1. in /var/www/accm.voilaah-dev.com/public_html/vendor/composer/platform_check.php on line 24

Who is depending on PHP 7.4?
Not OC v2.x for sure, right?

composer.json

{
    "name": "october/october",
    "description": "Built using October CMS: The Laravel-Based CMS Engineered For Simplicity",
    "type": "project",
    "homepage": "https://octobercms.com",
    "license": "proprietary",
    "require": {
        "php": ">=7.2.9",
        "october/rain": "^2.0",
        "laravel/framework": "^6.0",
        "october/all": "^2.0",

It is probably a plugin that wants a higher PHP version. Technically, the October CMS v2 platform can run on 7.2.9 but PHP added some features in 7.4 that can trip up older versions, so some plugin authors may require it instead of retrofitting their code.

Thanks, that makes sense. I updated the PHP version and seems to be rolling forward now.