Add support for Symfony 8

[DimaSorokin]

Hi!

Summary

This PR adds support for Symfony 8 while maintaining backward compatibility with Symfony 6.x and 7.x.

Closes: #742

Changes Made

composer.json:

• Updated all symfony/* dependencies to support ^6.0 || ^7.0 || ^8.0
• Updated minimum PHP version to ^8.4 to align with Symfony 8 requirements

Code updates:

• Updated type hints in classes to be compatible with Symfony 8
• Fixed tests to work with the new Symfony version

Testing

I have tested all major bundle features on a Symfony 8.0 project:

Producers:

• rabbitmq:stdin-producer - basic message publishing
• rabbitmq:stdin-producer --route=<key> - publishing with routing keys
• Producer service injection and programmatic usage

Consumers:

• rabbitmq:consumer - single consumer execution
• rabbitmq:multiple-consumer - multiple consumers on shared queues

Routing:

• Topic exchange with pattern matching (*.error, app.*, #)
• Direct exchange with specific routing keys
• Multiple consumers bound to the same queue (load balancing)
• Multiple routing keys per consumer

All commands execute successfully without any deprecation warnings or errors on Symfony 8.0.

Notes for Reviewers

This is my first contribution to an open-source project, and I'm new to the contribution process. I've done my best to:

• Follow the existing code style
• Test thoroughly on Symfony 8
• Maintain backward compatibility

I would greatly appreciate any feedback on:

• Code quality and implementation approach
• Any project conventions I might have missed
• Documentation updates that should be included

Please feel free to request any changes or improvements. I'm eager to learn and happy to make adjustments to meet the project's standards.

Thank you for maintaining this excellent bundle! 🙏