Fix PHP 8.4 implicit nullable parameter deprecations in Predis library

PHP 8.4 deprecates implicitly nullable parameter types. Parameters with a default value of `null` must now be explicitly marked as nullable (e.g., `?Type $var = null`).

This change updates the vendored `Predis` library in `plugins/cache-redis/` to comply with this requirement. It scans for function signatures like `Type $var = null` and updates them to `?Type $var = null`. This ensures compatibility with PHP 8.4 and PHP 8.5 while maintaining backward compatibility.

Affected files include `Predis` interfaces, connection classes, and command definitions.
Also updated PHPDoc `@method` annotations to reflect nullable types.

plugins/cache-redis/Predis/Connection/Replication/SentinelReplication.php

@@ -123,7 +123,7 @@ class SentinelReplication implements ReplicationInterface
         $service,
         array $sentinels,
         ConnectionFactoryInterface $connectionFactory,
-        ReplicationStrategy $strategy = null
+        ?ReplicationStrategy $strategy = null
     ) {
         $this->sentinels = $sentinels;
         $this->service = $service;