Nullable Causes a Validation Error

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Describe the bug

The `Nullable` causes a weird issue on the model validation when it's enabled

### Expected Behavior

The model should be valid regardless of the `Nullable` option

### Steps To Reproduce

1. Create an ASP.NET Core application
2. Add a model with some properties with `Required` attribute and some without
3. Check the model using `ModelState.IsValid`
4. If the `Nullable` is enabled in the project, which is the default behavior, the model is invalid

### Exceptions (if any)

The `ModelState.IsValid` should be `true` if there's no issue in the data annotation attributes

### .NET Version

_No response_

### Anything else?

_No response_