[Bug]: `export * from '...'` generate wrong dts code

### Reproduction link or steps

https://github.com/himself65/tsdown-issue-invalid-exports

### What is expected?

```ts
export type { UniqueType } from './utils'
```


### What is actually happening?

Generated the wrong type

```ts
import { t as utils_d_exports } from "./utils-Cs5BtkBm.js";
export { type UniqueType };
```

### Any additional comments?

_No response_