feat: add experimental annotation #5285

Job	Run time
sample_operators_tests (sample-operators/mysql-schema)	2m 37s
sample_operators_tests (sample-operators/tomcat-operator)	2m 34s
sample_operators_tests (sample-operators/leader-election)	3m 25s
sample_operators_tests (sample-operators/webpage)	2m 58s
	11m 34s

Provide feedback