paraviewsdk: make MPI-using tests conditional

tests/paraviewsdk.test.cmake

@@ -70,15 +70,19 @@ if (gui_enabled)
   add_paraviewsdk_example_app_test(ParticlesViewer)
 endif ()
 
-add_paraviewsdk_example_catalyst_test(CFullExample)
+if (mpi_enabled)
+  add_paraviewsdk_example_catalyst_test(CFullExample)
+  add_paraviewsdk_example_catalyst_test(CxxImageDataExample)
+  add_paraviewsdk_example_catalyst_test(CxxMappedDataArrayExample)
+  add_paraviewsdk_example_catalyst_test(CxxMultiPieceExample)
+  add_paraviewsdk_example_catalyst_test(CxxPVSMPipelineExample)
+  add_paraviewsdk_example_catalyst_test(MPISubCommunicatorExample)
+endif ()
+
 add_paraviewsdk_example_catalyst_test(CFullExample2)
 add_paraviewsdk_example_catalyst_test(CxxFullExample)
-add_paraviewsdk_example_catalyst_test(CxxImageDataExample)
-add_paraviewsdk_example_catalyst_test(CxxMappedDataArrayExample)
-add_paraviewsdk_example_catalyst_test(CxxMultiPieceExample)
 add_paraviewsdk_example_catalyst_test(CxxNonOverlappingAMRExample)
 add_paraviewsdk_example_catalyst_test(CxxOverlappingAMRExample)
-add_paraviewsdk_example_catalyst_test(CxxPVSMPipelineExample)
 add_paraviewsdk_example_catalyst_test(CxxParticlePathExample)
 add_paraviewsdk_example_catalyst_test(CxxSOADataArrayExample)
 add_paraviewsdk_example_catalyst_test(CxxVTKPipelineExample)
@@ -86,7 +90,6 @@ if (NOT CMAKE_GENERATOR MATCHES "Ninja")
   add_paraviewsdk_example_catalyst_test(Fortran90FullExample)
   add_paraviewsdk_example_catalyst_test(FortranPoissonSolver)
 endif ()
-add_paraviewsdk_example_catalyst_test(MPISubCommunicatorExample)
 add_paraviewsdk_example_catalyst_test(PythonDolfinExample)
 
 if (gui_enabled)