Bugfix: remove relative inc paths

[w4bremer]

📑 Description

This removes the relative include path to the logger header file in the apigear library.

Closes #90

✅ Checks

• [ ] My pull request adheres to the code style of this project
• [ ] My code requires changes to the documentation
• [ ] I have updated the documentation as required
• [x] All the tests have passed

ℹ Additional Information