update framework configuration reference for cache

Author: MrYamous

reference/configuration/framework.rst

@@ -2877,9 +2877,9 @@ app
 **type**: ``string`` **default**: ``cache.adapter.filesystem``
 
 The cache adapter used by the ``cache.app`` service. The FrameworkBundle
-ships with multiple adapters: ``cache.adapter.apcu``, ``cache.adapter.doctrine``,
-``cache.adapter.system``, ``cache.adapter.filesystem``, ``cache.adapter.psr6``,
-``cache.adapter.redis``, ``cache.adapter.memcached`` and ``cache.adapter.pdo``.
+ships with multiple adapters: ``cache.adapter.apcu``, ``cache.adapter.system``,
+ ``cache.adapter.filesystem``, ``cache.adapter.psr6``, ``cache.adapter.redis``,
+ ``cache.adapter.memcached`` and ``cache.adapter.pdo``.
 
 There's also a special adapter called ``cache.adapter.array`` which stores
 contents in memory using a PHP array and it's used to disable caching (mostly on