Configuration mismatch between swh.indexer.journal_client and the configuration declared in puppet

The configuration for the swh.indexer.journal_client declared in puppet has the following shape:

lang=yaml
swh::deploy::indexer_journal_client::config:
  journal:
    brokers: "%{alias('swh::deploy::journal::brokers')}"
    group_id: swh.indexer.journal_client
  scheduler: "%{alias('swh::remote_service::scheduler::config::writable')}"

Unfortunately, the currently released indexer journal client takes a configuration with a different shape (it takes a top level brokers and group_id).

I think the indexer journal client should be updated for the new config schema, but we can certainly use the old schema in puppet instead.

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Migrated from T2603 (view on Phabricator)