minor #11545 Document Redis Sentinel support for Cache (StephenClouse)

This PR was squashed before being merged into the master branch (closes #11545).

Discussion
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Document Redis Sentinel support for Cache

Accompanying docs for symfony/symfony#31437

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4cfe39b Document Redis Sentinel support for Cache

Author: javiereguiluz

components/cache/adapters/redis_adapter.rst

@@ -94,10 +94,21 @@ Below are common examples of valid DSNs showing a combination of available value
         'redis:?host[localhost]&host[localhost:6379]&host[/var/run/redis.sock:]&auth=my-password&redis_cluster=1'
     );
 
+    // Redis Sentinel is also supported in the same way
+    // set the redis_sentinel parameter to the name of your service group
+    // Sentinel support also requires the Predis library
+    RedisAdapter::createConnection(
+        'redis:?host[redis1:26379]&host[redis2:26379]&host[redis3:26379]&redis_sentinel=mymaster'
+    );
+
 .. versionadded:: 4.2
 
     The option to define multiple servers in a single DSN was introduced in Symfony 4.2.
 
+.. versionadded:: 4.4
+
+    Redis Sentinel support was introduced in Symfony 4.4.
+
 .. note::
 
     See the :class:`Symfony\\Component\\Cache\\Traits\\RedisTrait` for more options