OnlineManager subscription doesn’t execute when going offline

[kripod]

Describe the bug
I just noticed that the built-in onlineManager instance emits a notification only when going online, but not when going offline.

To Reproduce

React.useEffect(
  () =>
    onlineManager.subscribe(() => {
      // Logs only `{ online: true }`, no matter what happens
      // Cannot detect going offline
      console.log({ online: onlineManager.isOnline() });
    }),
  [],
);

Expected behavior
OnlineManager should listen to the "offline" event of browsers, besides just "online".

Desktop (please complete the following information):

• OS: macOS 11.1
• Browser: Firefox
• Version: 84.0.2 (64-bit)

Additional context
It seems like the default listener in OnlineManager doesn’t listen for "offline" events: https://github.com/tannerlinsley/react-query/blob/ac342e237ae9fab6759f2d7be616662da6c16225/src/core/onlineManager.ts#L51-L63

[tannerlinsley]

🎉 This issue has been resolved in version 3.5.13 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀