Remove the Pixi entrypoint in Trame applications

[evilkermit]

Summary of Changes

This removes the Pixi ENTRYPOINT in our Trame Dockerfiles. To get equivalent functionality, we need to give the Trame user access to /root in the image so that they can directly call the pixi command and add the pixi command to the default tool XML file.

Checklist

• The PR has a clear and concise title
• Code is self-documented and follows style guidelines.
• Automated tests are written and pass successfully.
• Regression tests (e.g. manually triggered system tests, manual GUI/tool tests, ...) are performed to make sure the PR does not break anything (when applicable)
• Readme file is present and up-to-date.

Documentation Updates

Additional Notes