While we're noodling on the topic, what else might be worth removing in Spark 4?
For example, looks like we're finally hitting problems supporting Java 8 through 21 all at once, related to Scala 2.13.x updates. It would be reasonable to require Java 11, or even 17, as a baseline for the multi-year lifecycle of Spark 4. Dare I ask: drop Scala 2.12? supporting 2.12 / 2.13 / 3.0 might get hard otherwise. There was a good discussion about whether old deprecated methods should be removed. They can't be removed at other times, but, doesn't mean they all *should* be. createExternalTable was brought up as a first example. What deprecated methods are worth removing? There's Mesos support, long since deprecated, which seems like something to prune. Are there old Hive/Hadoop version combos we should just stop supporting?
