Symfony version(s) affected: >=4.4

Description

#35851 introduced a BC break with json columns. Previously when using @var mixed and @ORM\Column(type="json") property info returned null for type so serializer accepted any value for this, but currently it always returns Type as builtin array and it doesn't accept anymore mixed values.

How to reproduce

will write if needed

Possible Solution

Return null for json type column, while leaving json_array column intact.

Additional context