Update dask-kubernetes to a newer kr8s

[jacobtomlinson]

Recently we unpinned kr8s but things broke, so the pin was set back to 0.9.0. We need to manually update the pin to something more recent (and in theory more stable) before unpinning again.

[dbalabka]

@jacobtomlinson , could you please specify what exactly has been broken? Is it related to #848, or are there any other tickets?

[jacobtomlinson]

@dbalabka I think box was the biggest change, but there was also a lot of shifting around in the port-forwarding code so we may need to do some more testing there.

[dbalabka]

@jacobtomlinson , I noticed the changes in the port forwarding. As far I understood, dask-kubernetes uses a new way to forward ports. I tested it and it fixes the problem with websockets for us. Therefore, we don't need to use NodePort any more.

[dbalabka]

@jacobtomlinson I will perform more tests and give a feedback in #805