vtree_learner_tests fails when GPU avaiable

[khosravipasha]

For some reason vtree_learner_test fails when CUDA is available even though the code does not seem to use GPU in that case.
The failure happens for the ":topdown" option.

$ julia --project=test test/structurelearner/vtree_learner_tests.jl 
prob circuit structure learn tests: Test Failed at C:\Users\Pasha\.julia\dev\ProbabilisticCircuits\test\structurelearner\vtree_learner_tests.jl:10
  Expression: variable(v) == partition
   Evaluated: 0x00000007 == 2
Stacktrace:

It does not fail on a machine with CUDA not enabled, but in the test the data is always on CPU and don't see anywhere that GPU would be used.

[khosravipasha]

seems to be fine now