isolatedDeclarations: error on setters

In:

```ts
export interface X {
  set value(_: string)
}
```

Error:

```
  x TS9013: Expression type can't be inferred with --isolatedDeclarations.
   ,-[src.ts:2:3]
 1 | export interface X {
 2 |   set value(_: string)
   :   ^^^^^^^^^^^^^^^^^^^^
 3 | }
   `----
```

The transform can output desired code, but the error exists and seems incorrect.