doc: update outdated OpenSSL 3.x strategy

[danbev]

Refs: #1207

[richardlau]

Refs: #1207

The ask in #1207 was to update the strategy for Node.js 17/18, and in particular the state of continued support for dynamically linking OpenSSL 1.1.1. My own view there is that we could say we support that for as long as OpenSSL 1.1.1 is in support.

Note that OpenSSL 1.1.1 is scheduled to go out of support after 2023-09-11 [1] which is before the End-of-Life dates for Node.js 18, but also Node.js 16 and we have to make a decision at some point regarding what we're going to do with Node.js 16. We have precedent before of shortening the expected lifespan of a Node.js LTS release (Node.js 8) to coincide with the end of support for the OpenSSL version it was built against. If we chose to do that we need to make that decision earlier and communicate that to the wider ecosystem.

(The strategy doc says

OpenSSL 1.1.1 goes EOL on 2023-09-11, which is before 16.x will go EOL, so is not an appropriate choice for 16.x

but OpenSSL 3.0.0 wasn't available when Node.js 16.x went out so we had no choice but to release on OpenSSL 1.1.1.)

We are using the quic fork of OpenSSL 1.1.1 -- I haven't seen any indication that they would differ regarding how long 1.1.1 would be supported for.

[1] https://www.openssl.org/policies/releasestrat.html

[danbev]

The ask in #1207 was to update the strategy for Node.js 17/1

This PR intentionally does not address the strategy, that is the reason for using Refs instread of Fixes. Sorry if that was confusing.

[mhdawson]

LGTM