Fix config.cpp include in CMakeLists.txt of systems_design (Case sensitive)

Description

Build fails on unix systems, because config.cpp was written with capital letter (Config.cpp) in CMakeLists.txt, but the file name is config.cpp.

Testing Instructions

1. Configure project
2. See succesfull configurateion of build project

Developer Checklist

• Code has been tested locally and/or in pipeline.
• Merge conflicts resolved with the target branch.

added modulesystems_design label

requested review from @ellen.seabrooke

enabled an automatic merge when all merge checks for 08a8ad08 pass

approved this merge request

merged

mentioned in commit 20fe6373