Reduce CAS errors in ApiEchoMarkSeen
Reduce CAS errors in ApiEchoMarkSeen

* These tend to log errors many times in a row for the same few
  users in any given time period. There is probably some usage
  pattern issue in JS on top of the abuse of preferences for
  such tracking state. In any case, this should help.

Bug: T95839
Change-Id: I4d57b1db43a63300a412a5de220b66081da754f1

wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo