Symfony version(s) affected: 5.1.6, 5.1.7

Description
Hello!

In one of our projects we have a class similar to this:

final class ExampleDTO{    private ?string $example;    public function __construct(?string $example)    {        $this->example = $example;    }    public function getExample(): string    {        return $this->example ?? 'fallback';    }}

It's used in the context of api platform, where incoming data is being deserialized to this object.

Before with Symfony 5.1.5 theexample property was detected as type?string, after upgrading to 5.1.6/5.1.7 it's only detected as typestring. Now when the incoming data contains a null value, it will fail withThe type of the "example" attribute must be "string", "NULL" given.

I did some tests and was able to track this new behaviour down to the property-info component. I suspect this change to be the reason:
#38041

It looks like now the return type ofgetExample() is used instead of the property type hint (?string).

So I would like to ask if this is the expected behaviour and if yes, how can I make the old way work again (somehow influence the priorities?). Thanks in advance!

How to reproduce
I created a reproducer here:
https://github.com/rogamoore/property-info-bug

Steps:

• Checkouthttps://github.com/rogamoore/property-info-bug/releases/tag/old-behaviour (property-info 5.1.5)
• Runcomposer install
• Runsymfony server:start
• Go tohttp://127.0.0.1:8000/
• Result:

^ array:1 [▼  0 => Symfony\Component\PropertyInfo\Type {#116 ▼    -builtinType: "string"    -nullable: true    -class: null    -collection: false    -collectionKeyType: null    -collectionValueType: null  }]

• Checkouthttps://github.com/rogamoore/property-info-bug/releases/tag/new-behaviour (property-info 5.1.6)
• Runcomposer install
• Runsymfony server:start
• Go tohttp://127.0.0.1:8000/
• Result:

^ array:1 [▼  0 => Symfony\Component\PropertyInfo\Type {#116 ▼    -builtinType: "string"    -nullable: false    -class: null    -collection: false    -collectionKeyType: null    -collectionValueType: null  }]

Additional context
PHP 7.4.10