Disable the remote dest store for the channel test

Dependencies

• [2] MQLCUSZL Test the fake derivations channel, asserting nested packages are properly represented.

Change contents

• replacement in t/Controller/Jobset/channel.t at line 8
  [2.653]→[2.653:676](∅→∅)
  − my %ctx = test_init();
  [2.653]

  [2.676]
  + my %ctx = test_init(

  + use_external_destination_store => 0

  + );