Declare make or ninja dependency for cmake but not both

Avoid declaring dependencies on the underlaying make or ninja for cmake modules depending on the actual one used by the module.

@ebassi , it's not a big deal and you may decide to keep the code as it is for simplicity. I'm proposing this because I've faced some cases on internal CI where we didn't deploy ninja (and where using the use-ninja="no" option accordingly) and jhbuild was failing because of the missing dependency on ninja.