Update updoate_instance_info_scheduler_spec to instances table has one or more rows

spec/workers/scheduler/update_instance_info_scheduler_spec.rb

@@ -5,6 +5,12 @@ require 'rails_helper'
 describe Scheduler::UpdateInstanceInfoScheduler do
   let(:worker) { described_class.new }
 
+  before do
+    stub_request(:get, 'https://example.com/.well-known/nodeinfo').to_return(status: 200, body: '{}')
+    Fabricate(:account, domain: 'example.com')
+    Instance.refresh
+  end
+
   describe 'perform' do
     it 'runs without error' do
       expect { worker.perform }.to_not raise_error