Remove testing include from ZFP worklet headers

Several of the ZFP worklet headers included `vtkm/cont/testing/
MakeTestDataSet.h`. This is a problem because if testing is turned off,
then `MakeTestDataSet.h` attempts to include a file that is not
generated, so the compile just fails if testing is off (and the testing
library is not on). This include must be a remanent of some old testing
code during development. It can be safely removed.
11 jobs for no-test-compile