fix: remove mention of legacy filelocking.enabled toggle

No longer relevant today since it's not an experiment feature and is now on by default. There is no good reason to disable it.

See #45330 & https://github.com/nextcloud/server/pull/45330#discussion_r1608291623

Signed-off-by: Josh <josh.t.richards@gmail.com>

admin_manual/configuration_files/files_locking_transactional.rst

@@ -22,8 +22,8 @@ the same document. Multiple users can open and edit a file at the same time and
 Transactional File locking does not prevent this. Rather, it prevents
 simultaneous file saving.
 
-File locking is enabled by default, using the database locking backend. This
-places a significant load on your database. Using ``memcache.locking`` relieves
+Transactional File locking will use the database locking backend by default. This
+places a significant load on your database. Setting ``memcache.locking`` relieves
 the database load and improves performance. Admins of Nextcloud servers with
 heavy workloads should install a memcache. (See
 :doc:`../configuration_server/caching_configuration`.)
@@ -32,7 +32,6 @@ To use a memcache with Transactional File Locking, you must install the Redis
 server and corresponding PHP module. After installing Redis you must enter a
 configuration in your ``config.php`` file like this example::
 
-  'filelocking.enabled' => true,
   'memcache.locking' => '\OC\Memcache\Redis',
   'redis' => array(
        'host' => 'localhost',
@@ -48,7 +47,6 @@ If you want to configure Redis to listen on an Unix socket (which is
 recommended if Redis is running on the same system as Nextcloud) use this example
 ``config.php`` configuration::
 
-  'filelocking.enabled' => true,
   'memcache.locking' => '\OC\Memcache\Redis',
   'redis' => array(
        'host' => '/var/run/redis/redis.sock',