release: flipping deprecated features to be fatal-by-default (#7549)

Signed-off-by: Alyssa Wilk <alyssar@chromium.org>

Mirrored from https://github.com/envoyproxy/envoy @ 7a554179105917400b254065d9f97669b3af7025

envoy/api/v2/cds.proto

@@ -188,7 +188,7 @@ message Cluster {
   //   **This field is deprecated**. Set the
   //   :ref:`load_assignment<envoy_api_field_Cluster.load_assignment>` field instead.
   //
-  repeated core.Address hosts = 7 [deprecated = true];
+  repeated core.Address hosts = 7;
 
   // Setting this is required for specifying members of
   // :ref:`STATIC<envoy_api_enum_value_Cluster.DiscoveryType.STATIC>`,