Updating to v2 fails in the CI on Node.js 12 & 14 with the following
error:

> npm ERR! Error while executing:
> npm ERR! /usr/bin/git ls-remote -h -t ssh://git@github.com/uNetworking/uWebSockets.js.git
> npm ERR!
> npm ERR! Warning: Permanently added the RSA host key for IP address '140.82.113.3' to the list of known hosts.
> npm ERR! git@github.com: Permission denied (publickey).
> npm ERR! fatal: Could not read from remote repository.
> npm ERR!
> npm ERR! Please make sure you have the correct access rights
> npm ERR! and the repository exists.
> npm ERR!
> npm ERR! exited with error code: 128

So we will revert the change for now.

Related: #4242

Labeled tuple elements were added in TypeScript 4.0.

Reference: https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-0.html#labeled-tuple-elements

Related: 44e20ba

Related: GHSA-273r-mgr4-v34f

Syntax:

```js
io.timeout(1000).emit("some-event", (err, responses) => {
  // ...
});
```

The adapter exposes two additional methods:

- `broadcastWithAck(packets, opts, clientCountCallback, ack)`

Similar to `broadcast(packets, opts)`, but:

* `clientCountCallback()` is called with the number of clients that
  received the packet (can be called several times in a cluster)
* `ack()` is called for each client response

- `serverCount()`

It returns the number of Socket.IO servers in the cluster (1 for the
in-memory adapter).

Those two methods will be implemented in the other adapters (Redis,
Postgres, MongoDB, ...).

Related:

- #1811
- #4163
- socketio/socket.io-redis-adapter#445

This is similar to `onAny()`, but for outgoing packets.

Syntax:

```js
socket.onAnyOutgoing((event, ...args) => {
  console.log(event);
});
```

This commit handles several edge cases that were silently ignored
before:

- receiving several CONNECT packets during a session
- receiving any packet without CONNECT packet first

Related:

- #4325
- dfederm/karma-jasmine-html-reporter#54

Related: #3933

Related: #4329

Release notes: https://github.com/socketio/engine.io/releases/tag/6.2.0
Diff: socketio/engine.io@6.1.3...6.2.0

Diff: 4.4.1...4.5.0