Implement parallel Happy Eyeballs as described in RFC 8305

What is the problem this feature will solve?

autoSelectFamily is enabled by default in Node.js 20. However, it does not properly implement parallel connection attempts, which are an integral part of the Happy Eyeballs algorithm. This can cause timeouts to occur that did not occur in versions prior to Node.js 20. See, for example, this discussion.

What is the feature you are proposing to solve the problem?

Implement the algorithm as described in Section 5 of RFC 8305:

Starting a new connection attempt does not affect previous attempts, as multiple connection attempts may occur in parallel.

What alternatives have you considered?

Disabling autoSelectFamily and restoring the pre-20 behavior, see https://github.com/nodejs/node/issues/47644#issuecomment-1554440759.

RFC 8305 の Section 5 から始め、そこにある並列接続試行の要件を、Node.js の現在の autoSelectFamily の動作と比較します。回帰を理解するために、リンクされた議論と issue で参照されている pre-20 の動作を確認してください。接続試行を以前の試行に影響を与えずに並列で進められ、報告されている timeout の動作にも対処できれば完了です。