Add pre-commit autoupdate workflow

[mikealfare]

Problem

We moved all linting and formatting dependencies into .pre-commit-config.yml. While this consolidates these tools and isolates the dev environment from these dependencies, it also hides them from dependabot.

Solution

Add a reusable workflow in dbt-labs/actions and call it here. This workflow will:

• run pre-commit autoupdate
• run pre-commit run --all-files
• submit a PR if updates were found

CI will take care of the verification of whether new conflicts were found in the updated pre-commit hooks.

The resulting PR: #297

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development, and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc.) or this PR has already received feedback and approval from Product or DX

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change. For details on how to document a change, see the contributing guide.

[emmyoop]

Looks good pending branch update

[VersusFacit]

Thanks for adding a test build.

[mikealfare]

I need to wait until the new secrets are added and then this can be merged.