Reactivate the ack late configuration for the high priority tasks

It's needed to disable the prefeching of the tasks by the workers. It can lead in situations where a task is prefetched by a worker loading a big repo. The prefetch task will remain blocked until the big repo loading is done.

Related to T3857

Test Plan

diff origin/production/worker0.internal.staging.swh.network current/worker0.internal.staging.swh.network
*******************************************
  File[/etc/softwareheritage/loader_high_priority.yml] =>
   parameters =>
     content =>
      @@ -22,4 +22,5 @@
       max_content_size: 104857600
       celery:
      +  task_acks_late: true
         task_broker: amqp://swhconsumer:swh-deploy-worker-task_broker-password@scheduler0.internal.staging.swh.network:5672/%2f
         task_queues:
*******************************************
*** End octocatalog-diff on worker0.internal.staging.swh.network

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Migrated from D6974 (view on Phabricator)