v2.1.1 - Security and minor dev improvements

What's Changed

• PHPStan improvements by @guillaume-sainthillier in #65
• Add phpstan-strict-rules by @BolZer in #67
• Bump symfony/process from 6.2.8 to 6.4.14 by @dependabot in #68

Full Changelog: v2.1.0...v2.1.1