[7.x] Add support for PhpRedis 5.3 options parameter

[tillkruss]

PhpRedis added a 7th parameter to support stream context options and Redis 6 authentication. This is particularly useful when a certificate is required to connect to Redis, or certificate verification needs to be disabled.

$redis = new Redis;

$redis->connect('127.0.0.1', 6379, 1, null, 0, 0, [
    'auth' => ['username', 'secret'],
    'stream' => [
        'verify_peer' => false,
    ],
]);

The database config would look like this (context should really be called options, but we already use that):

return [

    'redis' => [

        'client' => env('REDIS_CLIENT', 'phpredis'),

        'options' => [
            'cluster' => env('REDIS_CLUSTER', 'phpredis'),
            'prefix' => env('REDIS_PREFIX'),
        ],

        'default' => [
            'host' => 'tls://127.0.0.1',
            'password' => 'secret',
            'port' => 6379,
            'database' => 0,

            // new:
            'context' => [
                'auth' => ['username', 'secret'],
                'stream' => [
                    'verify_peer' => false,
                ],
            ]
        ],

    ],

];

For cluster connections, the context would be pulled from redis.options.context.