chore: update version to 999-SNAPSHOT #6606

Job	Run time
sample_operators_tests (sample-operators/leader-election)	3m 48s
sample_operators_tests (sample-operators/metrics-processing)	18m 23s
sample_operators_tests (sample-operators/tomcat-operator)	2m 46s
sample_operators_tests (sample-operators/mysql-schema)	3m 31s
sample_operators_tests (sample-operators/webpage)	4m 0s
	32m 28s

Provide feedback