Remove deprecated params from `IncidentManagement::ProcessAlertWorker`

The following discussion from !34948 (merged) should be addressed:

• @tkuah started a discussion: (+1 comment)

  Is it safe to remove arguments from the worker, or should we follow https://docs.gitlab.com/ee/development/sidekiq_style_guide.html#remove-an-argument ?

Remove deprecated _project_id and _alert_payload params from IncidentManagement::ProcessAlertWorker.

⚠ That should be done starting from 14.0 release.

More info about removing an arguments from Sidekiq workers. https://docs.gitlab.com/ee/development/sidekiq_style_guide.html#remove-an-argument