enumsAsConst does not work with futureProofEnums

**Describe the bug**

Enabling `enumsAsConst` quietly ignores `futureProofEnums`.

**To Reproduce**
Steps to reproduce the behavior:

Enable `enumsAsConst` and `futureProofEnums`.

https://codesandbox.io/s/awesome-cohen-25m6r?file=/types.ts

1. My GraphQL schema:

```graphql
enum Foo {
BAR
BAZ
}
```

2. My GraphQL operations:

```graphql
N/A
```

3. My `codegen.yml` config file:

```yml
schema: schema.graphql
documents: document.graphql
generates:
types.ts:
plugins:
- typescript
config:
futureProofEnums: true
enumsAsConst: true

```

**Expected behavior**

`Foo` enum should describe `'%future added value'`.

```ts
export const Foo = {
Bar: 'BAR',
Baz: 'BAZ',
futureAddedValue: '%future added value',
} as const;
```

Instead I am getting:

```
export const Foo = {
Bar: 'BAR',
Baz: 'BAZ',
} as const;
```