chore: remove pipeline legacy2023

[amatissart]

Description

Now that the new pipeline is operational in production, let's remove what is obsolete and simplify when possible.

Checklist

• [x] I added the related issue(s) id in the related issues section (if any)
  • if not, delete the related issues section
• [x] I described my changes and my decisions in the PR description
• [x] I read the development guidelines of the CONTRIBUTING.md
• [x] The tests pass and have been updated if relevant
• [x] The code quality check pass