Configruable scaling cool down period

[BitTheByte]

Implement a way to set a cool-down period for adaptive scaling instead of the hardcoded

dask-kubernetes/dask_kubernetes/operator/controller/controller.py

Line 816 in 92714da

cooldown_until = time.time() + 15

e.g.

apiVersion: kubernetes.dask.org/v1
kind: DaskCluster
metadata:
  annotations:
    kubernetes.dask.org/cooldown-until-interval: "30s"
  name: dask-f3a0c12f
  namespace: default
spec:
  ....

[jacobtomlinson]

Agreed this is a great idea.