Add cron to cleanup dangling single tests and batch periodic test reports #1610

Job	Run time
build-docker (internet.nl, docker/Dockerfile, app)	1m 3s
build-docker (unbound, docker/Dockerfile, unbound)	1m 6s
build-docker (linttest, docker/Dockerfile, linttest)	1m 19s
build-docker (test-runner, docker/test-runner.Dockerfile)	56s
build-docker (webserver, docker/webserver.Dockerfile)	1m 15s
build-docker (grafana, docker/grafana.Dockerfile)	54s
build-docker (util, docker/util.Dockerfile)	46s
integration-test	3m 35s
docs	1s
batch-integration-test	2m 51s
development-environment-test	2m 27s
lint/check	53s
test	2m 28s
	19m 34s

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