Updated TUE variable names

[MatthijsBurgh]

Tested with the master branch of tue-env, tue-env#58854fd6efd03bd5700e0a6039c7a8dcb72dad79, in three different situations:

• https://github.com/tue-robotics/tue-robotics.github.io/actions/runs/8876108892
• https://github.com/tue-robotics/ed/actions/runs/8876682906
• https://github.com/tue-robotics/pykdl_ros/actions/runs/8879165488