Allow Symfony 8

[daFish]

This change allows the installation with Symfony 8. It also installs symfony/var-exporter to be compatible with Doctrine ORM 3.0.

[barbieswimcrew]

really looking forward to this <3

[mwansinck]

@daFish I tried to use your fork and found some issues;

------ ------------------------------------------------------------------------------------------------------------------- 
  Line   src/DataCollector/DataTableDataCollector.php                                                                       
 ------ ------------------------------------------------------------------------------------------------------------------- 
  43     Call to an undefined static method Symfony\Bundle\FrameworkBundle\DataCollector\AbstractDataCollector::__sleep().  
 ------ ------------------------------------------------------------------------------------------------------------------- 

https://github.com/symfony/symfony/blob/8.0/UPGRADE-8.0.md#httpkernel

 ------ ------------------------------------------------------------------------------ 
  Line   src/Request/HttpFoundationRequestHandler.php                                  
 ------ ------------------------------------------------------------------------------ 
  51     Call to an undefined method Symfony\Component\HttpFoundation\Request::get().  
  108    Call to an undefined method Symfony\Component\HttpFoundation\Request::get().  
  125    Call to an undefined method Symfony\Component\HttpFoundation\Request::get().  
 ------ ------------------------------------------------------------------------------ 

https://github.com/symfony/symfony/blob/8.0/UPGRADE-8.0.md#httpfoundation

[daFish]

@mwansinck Will check it.

[davidnectarestudio]

thanks @daFish