TypeError dead catch when assigning mixed to int in property

### Discussed in https://github.com/phpstan/phpstan/discussions/9145

<div type='discussions-op-text'>

<sup>Originally posted by **GMQS** April  4, 2023</sup>
When assigning mixed data to a narrower type, a TypeError is said to be uncaught.
I am using PHPStan at level 8.
Is this behavior correct?

https://phpstan.org/r/f49b839d-dd70-43c7-9f69-2dab324a12e6</div>