deployments: add a description to manual deployments

[gustavovalverde]

Motivation

When running a workflow manually, using workflow_dispatch, it's commonly done with some reasoning behind it. But the machines on GCP don't have this reasoning exposed anywhere, and neither on the GitHub Action.

Designs

Add a field to add reasoning for doing a specific manual deployment, and keep this information available in GitHub Actions and in GCP.

[dconnolly]

I know I would will several of these with "test" :P

[conradoplg]

This would be useful, there's a bunch of deployments that I have no idea if we can delete or not 😆

Is there anything in particular about this that you'd like feedback on?

[mpguerra]

closing as stale