[fix] Cannot send secure cookie over unencrypted connection

## Describe the bug

**Node.js version:** v18.17.1

**OS version:** macOS 13.5.2 (22G91)

**Description:** I am trying to test against a Koa API that sets a HTTP cookie with a secure flag true, but when the API does that, I get the error "Cannot send the secure cookie over unencrypted connection".
I know the cookie module throws this error, but the problem is related to the supertest request which is a HTTP request, not a HTTPS.

## Actual behavior

- Supertest request does not support secure HTTP request

## Expected behavior

- Supertest request supports HTTP request

## Code to reproduce

### setCookie function
```ts
const DEFAULT_MAX_AGE = 7 * 24 * 60 * 60 * 100;

export const setCookie =
(koaContext: Context) =>
(cookieName: string, token: string, maxAge: number = DEFAULT_MAX_AGE) => {
try {
const domain = null;
const secure = config.NODE_ENV !== 'development';
const sameSite = config.APP_ENV === 'development' ? 'Lax' : 'None';

const options = {
httpOnly: true,
overwrite: true,
maxAge,
secure,
domain,
signed: false,
sameSite,
};

koaContext.cookies.set(cookieName, token, options);
} catch (err) {
console.log('set cookie failed: ', err);
}
};
```

### supertest request
```ts
const response = await request(app.callback())
.post('/api')
.set({
Accept: 'application/json',
'Content-Type': 'application/json',
})
.send(JSON.stringify(payload));
```

## Checklist

- [x] I have searched through GitHub issues for similar issues.
- [x] I have completely read through the README and documentation.
- [x] I have tested my code with the latest version of Node.js and this package and confirmed it is still not working.

The issue provides no repository file or test to start from; reproduce it from the shown request(app.callback()) call against a Koa app that sets a secure cookie. Trace the request and response handling for this case, and consider the work complete only when a regression test demonstrates the intended behavior without the reported error.

Written by the indexing model from the issue text.