Only test NeoN in CI

[yhmtsai]

Motivation

I do not think testing the dependence in the upstream library is a good practice.
It should be the job from the downstream library.
With exasim-project/NeoFOAM#137 or dependabot, we can easily and frequently update the NeoN version.
If it raises any issue on FoamAdapter, FoamAdapter will notice it on its own repo and need to adapt it. If it is an issue from NeoN, create an issue on NeoN. (Like what to do when Ginkgo has issues in NeoN).
Only fix version not make the complex CI setup between two repo.

[github-actions]

Thank you for your PR, here are some useful tips:

• If this is your first PR, please add yourself to the AUTHORS.md file
• Use labels to change the workflow behavior. Set auto-fix to automatically apply fixes, full-ci for a comprehensive set of tests and sanitizer runs, ready-for-review to show that you're done and need a review.
• I deployed a test documentation to https://exasim-project.com/NeoN/Build_PR_400
• For full-ci builds benchmark results are available at https://github.com/exasim-project/NeoFOAM-BenchmarkData/400
• Also check if the GPU pipelines on https://gitlab-ce.lrz.de/greole/neon/-/jobs are successful.