WHAT

In MGDSTRM-9839, we're renaming this metric, and putting a recording rule in its place, so we want to remove that recording rule once it's not being used any longer.

Once MGDSTRM-10074 has been rolled out so that the new name is also the default in the JMX exporter config, then the relabeling to convert the old name to the new name can also be removed.

WHY

It's a per-partition metric so it will have a lot of instances in Prometheus, so not having two of everything seems better.

HOW

Wait until blocking tasks are completed, then remove the recording rule created as part of MGDSTRM-9839.