[Bug][http-client-js]: optional body properties should not be generated in operation options

### Describe the bug

With the given typespec
```ts
@service
namespace Test;

model Widget {
id: string;
name: string;
age?: string;
@header foo?: string;
}

@post op create(@bodyRoot widget: Widget): void;
```
The operation options we generate is
```ts
export interface CreateOptions extends OperationOptions {
age?: string; // which should not exist here
foo?: string;
}
```

### Reproduction

N/A

### Checklist

- [x] Follow our [Code of Conduct](https://github.com/microsoft/typespec/blob/main/CODE_OF_CONDUCT.md)
- [x] Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
- [x] Check that this is a concrete bug. For Q&A open a [GitHub Discussion](https://github.com/Microsoft/typespec/discussions).
- [x] The provided reproduction is a [minimal reproducible example](https://stackoverflow.com/help/minimal-reproducible-example) of the bug.