chore: update blank nodes in tests #435

Job	Run time
check-cube (ubuntu-latest, 20, basic-cube-constraint)	37s
check-constraint (ubuntu-latest, 20)	38s
check-cube (ubuntu-latest, 20, standalone-constraint-constraint)	45s
check-constraint (windows-latest, 20.12.1)	3m 14s
check-cube (ubuntu-latest, 20, profile-visualize)	1m 9s
check-cube (ubuntu-latest, 20, profile-opendataswiss)	35s
check-cube (ubuntu-latest, 20, profile-opendataswiss-lindas)	37s
check-cube (windows-latest, 20.12.1, basic-cube-constraint)	2m 25s
check-cube (windows-latest, 20.12.1, standalone-constraint-constraint)	2m 48s
check-cube (windows-latest, 20.12.1, profile-visualize)	3m 52s
check-cube (windows-latest, 20.12.1, profile-opendataswiss)	2m 25s
check-cube (windows-latest, 20.12.1, profile-opendataswiss-lindas)	3m 54s
	22m 59s

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