Verify whether generated files are in sync

[gligneul]

📚 Context

We are committing generated text files to the repo because it is more straightforward. However, if someone forgets to update the generated file, it will get out of sync.

I would rather not commit these files in CI or generate them on demand.

✔️ Solution

Add a CI job that generates the files and checks if they are out-of-sync. If that is the case, the person will be forced to fix their PR before merging it.

Currently, we generate files with:

• go generate
• go run ./cmd/gen-docs
• This file https://github.com/cartesi/rollups-node/blob/main/offchain/graphql-server/src/schema/generate_schema.rs

🐢

Also, let's add an "auto-generated" warning to the files as discussed at #170 (comment)

[gligneul]

We should probably set-up a tools.go file to track the Go tools we use with go generate. See https://marcofranssen.nl/manage-go-tools-via-go-modules