fix(D005_01_inc): create the entity with a speed that the update can change

D005_01_inc sends a partial update of "speed" without a datasetId
(vehicle-speed-two-datasetid-01-fragment.jsonld, value 99), so the
update targets the default instance of speed. But the entity is created
from vehicle-simple-different-attributes.jsonld, whose only speed
instance has the datasetId urn:ngsi-ld:Property:speedometerA4567-speed2.
There is no default instance to update, so the local value stays 56 and
"Should Not Be Equal ${old_speed} ${new_speed}" fails.

Create the entity from vehicle-speed-attribute.jsonld instead: the same
speed (56) as a default instance. The fragment, shared with five other
tests, stays as it is.

(cherry picked from commit 7fc393165922f0beda24c25985327df702b5573e)