Upgrade daskhub chart version to 2021.12.0

[github-actions[bot]]

Upgrades daskhub chart version from 4.5.6 to 2021.12.0.

• [ ] Inspect eventual dependency changes between JupyterHub and Dask-Gateway here.
• [ ] If needed, inspect the JupyterHub chart's changelog.
• [ ] If needed, inspect the Dask-Gateway repo for changes, there is currently no changelog maintained.

[consideRatio]

Sections like these are no longer supported in the JupyterHub 0.11.1 version that this is upgrading to.

https://github.com/pangeo-data/pangeo-cloud-federation/blob/0b4e487d78e0ff28db768f895772420876ed2c44/deployments/gcp-uscentral1b/config/common.yaml#L144-L164

There is a quite clear error message if you try to helm upgrade or helm template declaring how to format the new configuration.

I cannot update the encrypted configuration under auth without the git-crypt key, but I can push commits to fix everything but that.

[scottyhq]

thanks @consideRatio , from here https://github.com/jupyterhub/zero-to-jupyterhub-k8s/blob/master/CHANGELOG.md looks like these are important changes related to security. happy to send you the git-crypt key via keybase or some by some other means that you prefer. i'm guessing the same recommended upgrade applies to pangeo binderhubs https://github.com/pangeo-data/pangeo-binder (which would also need upgrading k8s versions from 1.15)

[consideRatio]

Thanks @scottyhq! I'm @consideratio on keybase, perhaps with a large R if its case sensitive.

The security issues relate only to JupyterHub 0.10.0-0.10.5, but the version of daskhub currently installed is 0.10.6 so no hurry.

[scottyhq]

ah ok. i'd prefer to let this sit then until we get more hands on deck to deal with things (https://github.com/2i2c-org/pangeo-hubs/issues/12). I sent you the git-crpyt keys directly.

@rabernat is also owner of a 'pangeo' group on keybase that was a way to centralize various secrets (pangeo bot tokens, auth0 credentials, etc.). as far as i can tell @rabernat as owner is the only person who can add members there