Change logger signature to fix php 8.4 deprecation

[demyan112rv]

This change for fix the next php 8.4 deprecation:

Deprecated: Happyr\MessageSerializer\Serializer::__construct(): 
Implicitly marking parameter $logger as nullable is deprecated, the explicit nullable type must be used instead in .../happyr/message-serializer/src/Serializer.php on line 24

[demyan112rv]

@Nyholm could you merge this PR and create a new tag?

[Nyholm]

Thank you

[demyan112rv]

@Nyholm could you create a new release 0.5.3 for this fix?

[Nyholm]

I'll tag after #53

I want the CI to be green