Fix HltLinePersistenceSvc test
This fixes the failing HltServices.line_persistence_svc
test by:
- Specifying the dependency on a previous test
HltServices.assign_first_tck
(this wasn't the cause of the failure in the nightlies, but would cause a failure if the tests were ran with-j
). - Using
std
Python bindings imported fromROOT
rather thancppyy
. The latter is broken in strange ways under GCC 9.
The second point is very weird. I don't have any idea why it happens, but this MR fixes the test so we can choose to accept it now and revisit once the underlying problem is fixed.