fix: notify lighthouse from backfill loop when new subgraph data is found #1578

Job	Run time
set-aws-region	4s
build-and-test	6m 55s
build-and-push-lighthouse-handler-image	0s
build-and-push-lighthouse-image	0s
build-and-push-cartographer-image	0s
build-and-push-watchtower-image	0s
build-and-push-monitor-poller-image	0s
build-and-push-monitor-image	0s
build-and-push-cartographer-handler-image	0s
build-and-push-relayer-image	0s
e2e-tests	0s
terraform-services-core-prod	0s
terraform-services-backend-prod	0s
terraform-services-core-prod-testnet	0s
terraform-services-core-staging-testnet	0s
terraform-services-backend-staging-testnet	0s
terraform-services-core-mainnet-staging	0s
terraform-infra	0s
terraform-services-backend-prod-testnet	0s
terraform-services-backend-mainnet-staging	0s
	6m 59s

Provide feedback