Required blocks in resources implemented with `terraform-plugin-framework` are listed as optional

### Terraform CLI and terraform-plugin-docs Versions

Terraform v1.8.2
on darwin_arm64

require github.com/hashicorp/terraform-plugin-docs v0.19.1

### Provider Code

```go
func (r *networkResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
resp.Schema = schema.Schema{
Attributes: map[string]schema.Attribute{
// Omitted
},
Blocks: map[string]schema.Block{
"ip_network": schema.ListNestedBlock{
NestedObject: schema.NestedBlockObject{
Attributes: map[string]schema.Attribute{
// Omitted
},
},
Validators: []validator.List{
listvalidator.IsRequired(),
listvalidator.SizeBetween(1, 1),
},
},
},
}
}
```

### Expected Behavior

`ip_network` block is listed as required (with min and max items)

### Actual Behavior

`ip_network` block is listed as optional

### Steps to Reproduce

1. `tfplugindocs` with provider that has required blocks implemented with `terraform-plugin-framework`.

### How much impact is this issue causing?

Medium

### Logs

_No response_

### Additional Information

Based on [discussion in discuss.hashicorp.com](https://discuss.hashicorp.com/t/plugin-framework-blocks-dont-have-required-field/50180) this is a known issue from while ago, but there was no issue in this repository about the bug.

### Code of Conduct

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