[gitlab-org/gitlab] Remove OKRs

### ROOT CAUSE The OKR functionality is being removed, necessitating the deletion of Objective and Key result types along with their associated documentation to clean up the codebase. ### CODE FIX 1. **Remove Work Item Types:** - **File:** `app/workflow/work_item_types.rb` - **Action:** Remove the lines defining `Objective` and `Key result` work item types. 2. **Remove OKR Documentation:** - **Files:** Locate and remove all documentation files related to OKRs, typically found in `docs/` directory. 3. **Update Database:** - **File:** `db/migrate/[timestamp]_remove_okr_types.rb` - **Action:** Create a migration to delete any database entries related to OKR types. **Example Code:**

ruby
# In app/workflow/work_item_types.rb
remove work_item_type :objective
remove work_item_type :key_result

# In db/migrate/[timestamp]_remove_okr_types.rb
class RemoveOKRTypes < ActiveRecord::Migration[6.0]
  def up
    WorkItemType.destroy_all(where: { type_name: %w[Objective KeyResult] })
  end

  def down
    # Revert if needed
  end
end


**Note:** Replace `type_name` values with the exact names used in your system.