Remove cron Job from `oc_jobs` when application disabled/removed

[Georgiy Sitnikov]

Steps to reproduce

Reference https://help.nextcloud.com/t/oc-jobs-cleanup-how-to/125278

1. Install Antivirus App and Setup it
2. Remove Antivirus App
3. Check oc_jobs that created job was not removed

jobs 	class
...
1 	OCA\Files_Antivirus\BackgroundJob\BackgroundScanner
...

Expected behaviour

oc_jobs should be cleaned up if application was deleted or disabled

Actual behaviour

oc_jobs contains job for Antivirus, even if it is not presented in a System

Server configuration

Operating system: Ubuntu 20.04

Web server: Apache/2.4.51

Database: mysql 10.3.31

PHP version: 7.4.24

Nextcloud version: 21.0.4