fixing tests for php8.4

Author: Jacq

.github/workflows/tests.yml

@@ -32,8 +32,10 @@ jobs:
     env:
       # The hostname used to communicate with the Redis service container
       REDIS_HOST: redis
+      REDIS_SENTINEL_HOST: redis-sentinel
       # The default Redis port
       REDIS_PORT: 6379
+      REDIS_SENTINEL_PORT: 26379
       # MySQL
       DB_DATABASE: test
       DB_USER: root

src/Prometheus/Storage/Redis.php

@@ -130,7 +130,7 @@ public function getRedisSentinel(): \RedisSentinel
      * @return self
      * @throws StorageException
      */
-    public static function fromExistingConnection(\Redis $redis, \RedisSentinel $redisSentinel = null): self
+    public static function fromExistingConnection(\Redis $redis, ?\RedisSentinel $redisSentinel = null): self
     {
         if (isset($redisSentinel)) {
             RedisSentinel::fromExistingConnection($redisSentinel);