Provide lazy-connection options

[nicolas-grekas]

Using ext-redis, it's possible to lazy-connect to a server by passing an option array to the constructor.
But in Relay, this isn't lazy:

php > $redis = new Relay\Relay([
php (     'host' => '127.0.0.1',
php (     'port' => 6379,
php ( ]);
PHP Warning:  Uncaught Relay\Exception: Connection refused (RELAY_ERR_IO; relay.c:4702) in php shell code:1

Relay\Cluster also should support lazy-connections, see phpredis/phpredis#2753

Note that this missing laziness capability forces us at Symfony to maintain userland lazy-proxies, eg. this one for relay:
https://github.com/symfony/symfony/blob/7.4/src/Symfony/Component/Cache/Traits/RelayProxy.php

Those are painful to maintain and we'd happily drop them once proper support is added to ext-relay and ext-redis.
(I'd say we might even consider deprecating support for relay if the burden is too high - and this is the most costly concern).

[tillkruss]

That's coming in v0.20 shortly ✌️

[tillkruss]

This was merged into our nightly builds and will release in v0.20.

[tillkruss]

Released with v0.20.0.