Stop skipping or remove skipped demos

[mscroggs]

ffcx/demo/test_demos.py

Lines 15 to 27 in d2f7e9f

	if file in [
	"MixedPoissonDual", # Discontinuous Raviart-Thomas
	"BiharmonicHHJ", # Hellan-Herrmann-Johnson
	"NodalMini", # NodalEnrichedElement
	"Mini", # EnrichedElement
	"MixedGradient", "TraceElement", # HDiv Trace
	"MassHdiv_2D_1", "MassHdiv_2D_3", "MixedPoisson", "MassHdiv_2D_2", # Brezzi-Douglas-Marini
	"MixedElasticity", # VectorElement of BDM
	"RestrictedElement",
	"_TensorProductElement"
	]:
	# Skip demos that use elements not yet implemented in basix
	pytest.skip()