deps: update dependency com.google.cloud:google-cloud-billingbudgets-bom to v2.1.6 (#3503)
deps: update dependency com.google.cloud:google-cloud-billingbudgets-bom to v2.1.6 (#3503)


googleapis/java-cloud-bom,googleapis/java-cloud-bom,googleapis/java-cloud-bom,googleapis/java-cloud-bom