Remove PHP-Parallel-Lint

[nicwortel]

PHPStan will also report syntax errors, so running PHP-Parallel-Lint is redundant.

• The pull request is complete according to the Definition of Done
  • Acceptance criteria in the ticket have been met
  • Automated tests are written according to the test plan
  • The documentation is up-to-date
  • Deployment automation includes newly introduced environment variables and credentials are added to the credentials.fact file of all servers
• The pull request has a descriptive title that describes what has changed, and provides enough context for the changelog
• When applicable, the pull request title starts with the issue number