[FLINK-36591] Remove `flink-contrib` #42

Job	Run time
Pre-compile Checks / Basic QA	8m 49s
Default (Java 8) / Compile	56m 48s
Default (Java 8) / E2E (group 1)	1h 38m 44s
Default (Java 8) / Test packaging/licensing	4m 1s
Default (Java 8) / Test (module: core)	29m 11s
Default (Java 8) / E2E (group 2)	5h 10m 9s
Default (Java 8) / Test (module: python)	30m 21s
Default (Java 8) / Test (module: table)	58m 55s
Default (Java 8) / Test (module: connect)	19m 3s
Default (Java 8) / Test (module: tests)	42m 58s
Default (Java 8) / Test (module: misc)	45m 29s
	11h 44m 28s

Provide feedback