Handle $reflectionProperty->getDefaultValueExpression() return null

[samsonasik]

Ref rector-doctrine test error https://github.com/rectorphp/rector-doctrine/actions/runs/4321563757/jobs/7542937994#step:5:19

 [ERROR] Could not process                                                      
         "/home/runner/work/rector-doctrine/rector-doctrine/src/NodeAnalyzer/Set
         terClassMethodAnalyzer.php" file, due to:                              
         "System error:                                                         
         "PHPStan\BetterReflection\Reflection\Adapter\ReflectionProperty::getDef
         aultValueExpression(): Return value must be of type                    
         PhpParser\Node\Expr, null returned"                                    
         Run Rector with "--debug" option and post the report here: 
https://github.com/rectorphp/rector/issues/new
". On line:

On PR rectorphp/rector-doctrine#154

[TomasVotruba]

Thank you 👍

Github Actions were down yesterday evening so I missed this.