message: cmake: Find our PNG dependency on behalf of consumers
diff: @@ -47,6 +47,11 @@ if(NOT @BUILD_SHARED_LIBS@)
  find_dependency(MGARD)
  endif()
  + set(ADIOS2_HAVE_PNG @ADIOS2_HAVE_PNG@)
  + if(ADIOS2_HAVE_PNG)
  + find_dependency(PNG)
  + endif()
  +
  set(ADIOS2_HAVE_DataSpaces @ADIOS2_HAVE_DataSpaces@)
  if(ADIOS2_HAVE_DataSpaces)
  find_dependency(DataSpaces)
  