Set PHP 7.4 as the minimum supported version or propose an official minimum version

[fadrian06]

Currently, the library does not explicitly state a minimum required PHP version.

I propose setting PHP 7.4 as the minimum required version for using this library, or alternatively, discussing and documenting an official minimum PHP version that is required and supported by the project.

Motivation:

• Clearly communicate minimum requirements to users
• Prevent future incompatibility issues
• Improve project documentation and transparency

Suggested tasks:

• Discuss with the team the most appropriate minimum PHP version (7.4 or higher)
• Update documentation (README, etc.) to reflect the minimum version
• Update composer.json to set "php": ">=7.4" or the agreed version

Thank you.