Fixes/do not override timestamps (#7336)

* Revert "Fixes/do not override timestamps (#7331)"

This reverts commit 581a5c9d29.

* Document Snowflake ID corner-case a bit more

Snowflake IDs are used for two purposes: making object identifiers harder to
guess and ensuring they are in chronological order. For this reason, they
are based on the `created_at` attribute of the object.

Unfortunately, inserting items with older snowflakes IDs will break the
assumption of consumers of the paging APIs that new items will always have
a greater identifier than the last seen one.

* Add `override_timestamps` virtual attribute to not correlate snowflake ID with created_at

app/workers/activitypub/processing_worker.rb

@@ -6,6 +6,6 @@ class ActivityPub::ProcessingWorker
   sidekiq_options backtrace: true
 
   def perform(account_id, body)
-    ActivityPub::ProcessCollectionService.new.call(body, Account.find(account_id))
+    ActivityPub::ProcessCollectionService.new.call(body, Account.find(account_id), override_timestamps: true)
   end
 end