Idea: Create GitHub Action workflow for installing dbc and drivers

[amoeba]

Many packaging tools have official GitHub Actions workflows that do things like installing the package manager, setting up caching, and installing packages. Doing this for dbc could be useful.

We could call it setup-dbc and it could look something like,

- uses: columnar-tech/setup-dbc@1.2.3
  with:
    dbc-version: v1.2.3
    cache: true
- run: dbc sync # <- this would take advantage of dbc.toml

edit: or the action could auto-sync?

[amoeba]

Completed via https://github.com/columnar-tech/setup-dbc. We should document it in the dbc docs so I'll open a new issue.