Improve Geo logging

It's often the case in Geo when logs bring no valuable information because the backtrace is lost. Example:

{"severity":"ERROR","time":"2023-02-21T17:48:10.958Z","correlation_id":"5b5bbe0b43a3595c9c4bb89c4b9d5ee0","class":"Geo::ContainerRepositorySyncService","host":"REDACT","message":"Container repository sync failed","project_id":6781,"project_path":"pd/do/p2/ci/ci","container_repository_name":"runtime/java","error":"undefined method `[]' for nil:NilClass"}

The common pattern we use is we call fail_registry_sync! where we call log_error(message, error). Only message is logged. I propose to log the first 3 lines of the backtrace and maybe join the last 3 too?!

e.backtrace.first(3).join("\n") + "..." + e.backtrace.last(3).join("\n")

cc @geo-team WDYT?