[Telemetry/Monitoring] Monitoring should stop collecting Kibana Usage in the .monitoring indices

[afharo]

Monitoring is collecting Kibana's Usage and storing them in the .monitoring indices:

• bulk_uploader is using usageCollection's APIs to retrieve the usage data every 24h.
• Metricbeat is calling /api/stats?extended&exclude_usage=false&legacy every 24h.

With the latest changes in #82638, it won't be needed anymore.

Planned action points (separate PRs):

• bulk_uploader should stop using usageCollection ([Monitoring] Stop collecting Kibana Usage in bulkUploader #83546):
  Ideally, bulk_uploader should only collect Kibana's OpsMetrics and the Settings (basically the StatsCollectors registered in the system. Changing it to collect this data by itself, would also allow us to remove the formatBulkUpload methods in the collectors (and their types).
  N.B.: The plans are to remove it entirely on 8.0, so we shouldn't sweat it too much on the refactoring.
• Metricbeat should stop using /api/stats?extended&legacy&exclude_usage=false ([Metricbeat][Kibana][stats] Stop collecting usage beats#22651)
• Remove from usageCollection the APIs that exist only for bulk_uploader ([UsageCollection] Remove formatBulkUpload and other unused APIs #84313)

[elasticmachine]

Pinging @elastic/kibana-telemetry (Team:KibanaTelemetry)

[elasticmachine]

Pinging @elastic/kibana-core (Team:Core)