extended validation modifies null-results to array if an errors occurs

**Describe the bug**

Given the following graphql schema:
```Graphql

type Something {
field: AType @auth(roles: ["my-role"]
}

type Query {
something(id: Int!) : Something
}
```

When querying for a `id` a user do not have access to the `something` is expected to return `null`. But when the generic-auth detects that the user do not have access to `field` since the user do not have role `my-role` it will generate an error.

Looking into the [extended-validation](https://github.com/graphql-hive/envelop/blob/main/packages/plugins/extended-validation/src/plugin.ts#L184C9-L188C18)

```typescript
console.log(newResult.data);
errors.forEach(e => {
if (e.path?.length) {
console.log("Before",e.path?.length,e.path, newResult.data)
newResult.data = visitPath(e.path, newResult.data);
console.log("After",e.path?.length, newResult.data)
}
});
```

We get the following sequence:
```
{ data: [Object: null prototype] { something: null } }

at Object.onResult (../../node_modules/@envelop/extended-validation/cjs/plugin.js:78:37)

console.log
Before [ 'something', 'field' ] [Object: null prototype] { something: null }
at ../../node_modules/@envelop/extended-validation/cjs/plugin.js:117:45
at Array.forEach ()

console.log
After 2 [Object: null prototype] { something: [] }
```

Im expecting it to still be `{something: null}`.

**Environment:**
- OS: Ubuntu 24.04.2 LTS
- NodeJS: v22.14.0
- @envelop/core: 5.2.3
- @envelop/extended-validation 5.1.3
- @envelop/generic-auth 9.1.3

Running graphql-yoga server with typegraphql.