cleanup the workflow impls

https://github.com/axodotdev/cargo-vet-school/tree/main/.github/workflows

Now that I've learned github-script lets you do inline JS, we *can* just kill the `certify` dir which exists to create a single JS workflow. Of course this would lock the current impl *even more* into github but it's also not exactly *complex* logic. The challenge is mostly getting github to not freak out about permissions and to trigger in the right situations, which is necessarily domain-specific.

There's also just a bunch of commented out gunk from experiments and bad formatting/style.

Not sure how much of this stuff should be "published actions".

Not sure how much should be abstracted into a new rust cli (or made into builtin functionality of cargo-vet!).

Start by reviewing the workflows under .github/workflows and the certify directory to map the current implementation and its commented experiments. Clarify whether the goal is a single inline-JavaScript workflow, published actions, or a Rust CLI, then define the intended permissions and trigger behavior as the completion criteria.

Written by the indexing model from the issue text.