[graphiql] Headers disappear with persistent enabled

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

The default behavior (at least on 3.0.0) seems broken:

1. Set Persist headers to On in the UI
Add headers
2. Reload, observe that headers are persisted, but that the setting has reverted
3. Reload again, observe that headers have now vanished

### Expected Behavior

Headers should persist if this option is enabled by the user, and the option should stick.

### Steps To Reproduce

See description.

### Environment

* GraphiQL Version: 3.0.0
* OS: any
* Browser: any
* Bundler:
* `react` Version:
* `graphql` Version:

### Anything else?

_No response_