You can do that, but such solutions should be rejected. The rules do
not say that trailing whitespace doesn't count.
The removal of trailing whitespace in the test programs was intentionally added during the TPR golfs because it turned out that people have the unfortunate habit of using editors where it's not very visible that they have extra trailing newlines, and where they had the winning solution without realizing it. And then these people wasted days trying to still improve their solution. Solving this problem of serious players was decided to be more important than stopping jokers playing games with trailing whitespace.
If people seriously think this is a problem I could change the way this case is handled in the generic test program skeleton. But currently I don't considere this well known abuse to be relevant enough for that.