[PP-1] Create Gitlab job to test Minimum PHP Language syntax

Problem/Motivation

In the past we have accidetnaly included PHP Syntax that is only supproted in newer versions of the PHP language.

It would be ideal to run phplint at our minimal supported language level on every MR.

We need 🐛 False postivie on PHP Parallel Lint control directive Active to be adopted before we can do do so.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes