ci: twister: Enable tests on bsim boards

Since the move to github workflows
e366d794
we lost the ability to run in CI in twister the bsim boards.
This means people cannot use the nrf52_bsim in normal twister
workflows even if it would work perfectly fine otherwise
(say as a stand alone test of the controller that does not
require an actual BT pair).
It also meant changes to the bsim board itself where not
tested with twister like for other boards, but relied solely
on the BT tests.

Enable this kind of tests again.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>