The xdcr audit events are removed in the 7.1 release

These audit events have been released in 7.1 via MB-47124 and should be removed from this doc. In reality these haven't been generated since prior to the 6.0 release.

code(xdcr_create_cluster_ref) ->
8213;
code(xdcr_update_cluster_ref) ->
8214;
code(xdcr_delete_cluster_ref) ->
8215;
code(xdcr_create_replication) ->
8216;
code(xdcr_update_replication) ->
8217;
code(xdcr_cancel_replication) ->
8218;
code(xdcr_update_global_settings) ->
8219;