fix(settings): specify VALID_RETENTION_DAYS for self-hosted #19803

Job	Run time
Dataset Config Validation	37s
detect what files changed	6s
Linting - Rust	2m 12s
pre-commit hooks	38s
Build snuba CI image	8m 0s
mypy typing	1m 11s
Publish Snuba to DockerHub	0s
validate-devservices-config	0s
Front end tests for snuba admin	1m 11s
self-hosted-end-to-end	11s
Tests and code coverage (test)	13m 6s
Tests and code coverage (test_rust)	4m 49s
Tests on multiple clickhouse versions (23.8.11.29.altinitystable)	13m 8s
sentry (0)	5m 54s
Tests and code coverage (test_distributed)	23m 2s
Tests on multiple clickhouse versions (24.3.5.47.altinitystable)	13m 21s
sentry (1)	5m 54s
Tests and code coverage (test_distributed_migrations)	3m 6s
sentry (2)	5m 50s
sentry (3)	7m 33s
	1h 49m 49s

Provide feedback