ci: add publiccode.yml validation workflow

[publiccode-pr-bot]

This PR adds a GitHub Actions workflow that validates publiccode.yml on every pull request using italia/publiccode-parser-action@v1.

No behavior change to the code, just CI.

[mboelen]

More clarification is needed before this can be approved. Why would we want to validate the publiccode.yml each pull request?

[bfabio]

@mboelen hi! This is basically a linter to make sure the publiccode.yml file is correct and respects the spec.

Maybe it can be improved by running it only when the file is modified.

on:
  pull_request:
    paths:
       - "publiccode.yml"

[mboelen]

Thanks for the response. That would make more sense, as doing it on every pull request seems to be a waste of resources.

You are connected to the publiccode project, right? Can you create an updated pull request?

[bfabio]

Yes, I'm the current maintainer. I'll push an update ASAP

[bfabio]

Opened as #1662