[DISCUSS] Dropping support for Spark 2.x

[wombatu-kun o_0]

Hi all,

Support for Spark 3.0, 3.1, 3.1 , 3.2 is already removed in Hudi master.
Dropping support for Java 8 - is planned.
Why do Hudi still support Spark 2.4? What do you think about dropping this
support too in the nearest future?