Remove testing properties for hyperdrive executor #743
Description
In v0.5.12, testing properties were introduced for the hyperdrive executor. Since the hyperdrive executor has proven to be reliable, they can be removed.
The following application property can be removed (and replaced by true): executors.enable.hyperdrive.executor
The method useHyperExecutor in Executors.scala can be removed (and replaced by true)
Data migration
In existing job templates, the application config useHyperdriveExecutor=true can be removed. Since it only concerns job templates, and keeping the application config will not break any workflows, this data migration can be done manually.