feat: add experimental annotation #5288

Job	Run time
sample_operators_tests (sample-operators/tomcat-operator)	3m 31s
sample_operators_tests (sample-operators/mysql-schema)	2m 32s
sample_operators_tests (sample-operators/leader-election)	3m 21s
sample_operators_tests (sample-operators/webpage)	3m 7s
	12m 31s

Provide feedback