Remove unnecessary stubFiles entry in phpstan.neon file

Problem/Motivation

i've oriented to CrowdSec when setting up the phpstan tests and copied over the stubFiles entry it was using due to a lack of understanding on my end at the time. but turns out those stubs are not necessary in the case of skipto.

parameters:
  level: 6
  ignoreErrors:
    - identifier: missingType.iterableValue

passes without any errors as well.

Steps to reproduce

Proposed resolution

Remove the stubfile line

Remaining tasks

User interface changes

API changes

Data model changes