Those are all consumed by our parser, so they all support comments.
I was considering whether they should have a license header at all,
but in the end I decided to add it because those files are often created
by copying parts of real unit files. And if the real ones have a license,
then those might as well. It's easier to add it than to make an exception.
The test currently fails in the check for LimitNOFILESoft/LimitNOFILE. I see
default values there. This doesn't seem to be related to the changes in the
test suite, but rather to the recent changes to pid1.