[CHORE] Tweaks to publish action

[sbarrio]

What does this PR do?

It fixes an issue with yarn clean and also sets up the action to run for real.

Motivation

We need to automate publishing and remove NPM tokens.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)
• If this PR is auto-generated, please make sure also to manually update the code related to the change