Adds Kaggle testing to CI workflow

[pculliton]

Using a restricted Kaggle account, this code:

• Adds an Ubuntu 20.04 build (required for glibc compat with Kaggle infra)
• Uploads the ubuntu-20.04 build and supporting library to a Kaggle dataset using a fork of push-kaggle-dataset
• Creates a new version of a Kaggle notebook that loads artifacts from the Kaggle Model Hub, along with the newly updated dataset, and validates a 2b-it-sfp model.
• Runs the notebook using an updated / owned fork of kaggle-action and throws an error if the process does not complete, raises an exception, or produces an invalid response.

Todo: add tests / capabilities to the smoke tests used by the notebook.