FN: overriding a property with a property of a different type doesn't report any error

# Bug report
https://phpstan.org/r/24066554-0a69-4a2c-9463-17d12b2958e1
https://3v4l.org/rH5Ea

### Expected output
This code should report an error.

In addition, the equivalent code with PHPDoc types should also be an error, since any change to a parent property's type can result in LSP violations (since they are both read/write).