Having many tests on the same group does make the LAVA overlay
too big for devices with small amount of free space. Thus some
tests randomly fail due to lack of space.

To make things worse, some old tests rely in packages like python
which are not part of the images and need to be installed, consuming
extra space.

To workaround this issue, split the test group in two, moving tests
with similar dependencies to a new to reduce the amount of space
required per group.

This will be fixed once tests will be moved from pkg/apertis-tests
to tests/ but in the meantime let's do the split to reduce the chance
of random failures.

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>