Adds a workflow that executes the 'glob' action on every push and pull
request to the 'release/next-js' branch.
(For now this is just staged to the 'jt/lacd' branch for testing.)
This action, when supplied with the appropriate arguments, will create a
Landscape glob from GITHUB_SHA [1] and deploy it OTA to the appropriate
ship.
It needs to be supplied the following:
* ship name
* base64-encoded GCP Service Account credentials
* a base64-encoded SSH secret key to be used for GCP actions
* the corresponding base64-encoded SSH public key
[1]: https://docs.github.com/en/free-pro-team@latest/actions/reference/environment-variables
