Fixed PHPStan issues

[mikadamczyk]

🎫 Issue	N/A

Description:

  Line   src/bundle/Command/MigrateLegacyMatrixCommand.php                      
 ------ ----------------------------------------------------------------------- 
  105    Argument of an invalid type array<SimpleXMLElement>|null supplied for  
          foreach, only iterables are supported.                                
         🪪  foreach.nonIterable                                                
  181    Parameter #1 $cells of method                                          
         Ibexa\Bundle\FieldTypeMatrix\Command\MigrateLegacyMatrixCommand::conv  
         ertCellsToRows() expects array<int|string, mixed>, array<SimpleXMLEle  
         ment>|null given.                                                      
         🪪  argument.type                                                      
 ------ ----------------------------------------------------------------------- 

 ------ ----------------------------------------------------------------------- 
  Line   src/lib/FieldType/Mapper/MatrixFormMapper.php                          
 ------ ----------------------------------------------------------------------- 
  64     Access to protected property                                           
         Ibexa\Contracts\ContentForms\Data\Content\FieldData::$fieldDefinition  
         .                                                                      
         🪪  property.protected                                                 
 ------ ----------------------------------------------------------------------- 

For QA:

Documentation:

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud