Use dependency injection in StaticPageSubscriber

Problem/Motivation

While fixing 🐛 Revision object is returned instead of revision id due to core type upcasting change. Needs review , eager contributors wanted to convert StaticPageSubscriber to use DI. I also ran into this while getting a green pipeline at 📌 Enable GitLab CI for static_page Active since phpstan was complaining about the \Drupal:: calls.

Steps to reproduce

Proposed resolution

1. Use DI not \Drupal:: in src/EventSubscriber/StaticPageSubscriber.php
2. Remove that warning from phpstan-baseline.neon

Remaining tasks

Move commits/diff about DI from 🐛 Revision object is returned instead of revision id due to core type upcasting change. Needs review into here.

User interface changes

API changes

Data model changes