Fix errcheck issues in server/channels/jobs/schedulers_test.go (#28970)

server/.golangci.yml

@@ -192,7 +192,6 @@ issues:
         channels/jobs/hosted_purchase_screening/worker.go|\
         channels/jobs/jobs.go|\
         channels/jobs/resend_invitation_email/worker.go|\
-        channels/jobs/schedulers_test.go|\
         channels/manualtesting/manual_testing.go|\
         channels/store/localcachelayer/channel_layer.go|\
         channels/store/localcachelayer/channel_layer_test.go|\