Allow Support PHP 8.0

[Yozhef]

Changelog

### Added
- Add support for PHP 8.0

[VincentLanglet]

A release is needed for sonata-project/datagrid-bundle

I'm on it: sonata-project/SonataDatagridBundle#317

[VincentLanglet]

Blocker by sonata-project/doctrine-orm-admin-bundle now

[jordisala1991]

We need the dev kit PR @Yozhef

[Yozhef]

@jordisala1991 yes, 5 min =)

[Yozhef]

@jordisala1991 sonata-project/dev-kit#1429

[wbloszyk]

@sonata-project/contributors @Yozhef
We have problem here. Some dependencies are not allowed for php 8.0.

composer why-not php 8.0
php-amqplib/php-amqplib  2.12.2  requires  php (>=5.6.3,<8.0)  

[VincentLanglet]

This is not a dependency https://github.com/sonata-project/SonataNotificationBundle/blob/3.x/composer.json#L23

[Yozhef]

@wbloszyk php-amqplib/php-amqplib in master support - ned wait release =(

[wbloszyk]

@wbloszyk php-amqplib/php-amqplib in master support - ned wait release =(

My bad, "php": ">=7.0",.

[Yozhef]

@wbloszyk ви праві зараз остання версія https://packagist.org/packages/php-amqplib/php-amqplib#2.12.2 не підтримує PHP 8.0 = (php:> = 5.6.3, <8.0 =( But its requered dev - deps I can't say for sure if it's important to abandon version 8 for now