Casting to int something that's already an int, while the value may not be an int

### Summary of a problem or a feature request

Sometimes, PHPStan thinks that a value is an int, while it may not be

### Code snippet that reproduces the problem

https://phpstan.org/r/ed0174a21527bd88cd51843f1f919fb7

### Expected output

PHPStan should not emit a warning here
