[CI] Remove dependency on test_param_file_ltv.py

This is a preparation to remove the test_param_file_ltv.py. It is almost a duplication of test_param_file.py and was created to be able to run long and short test vectors in the same pytest command. Now, we concluded we do not want to do this, and it is better to remove the duplicated code. It has already started to diverge.

All tests should be identical.