test: Fix race in check-packagekit PackageKit crash test
test: Fix race in check-packagekit PackageKit crash test

There's a race in this test which expects a certain number of
pre elements to be present. Remove the race.

Closes #9313
moraleslazaro/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,cockpituous/cockpit,martinpitt/cockpit,garrett/cockpit,SotolitoLabs/cockpit,cockpit-project/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit,martinpitt/cockpit,stefwalter/cockpit,SotolitoLabs/cockpit,stefwalter/cockpit,mareklibra/cockpit,cockpit-project/cockpit,moraleslazaro/cockpit,stefwalter/cockpit,mvollmer/cockpit,mareklibra/cockpit,cockpit-project/cockpit,deryni/cockpit,cockpituous/cockpit,SotolitoLabs/cockpit,cockpituous/cockpit,mareklibra/cockpit,andreasn/cockpit,cockpit-project/cockpit,SotolitoLabs/cockpit,andreasn/cockpit,stefwalter/cockpit,martinpitt/cockpit,andreasn/cockpit,mvollmer/cockpit,mareklibra/cockpit,martinpitt/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,deryni/cockpit,mvollmer/cockpit,andreasn/cockpit,garrett/cockpit,garrett/cockpit,mareklibra/cockpit,SotolitoLabs/cockpit,mareklibra/cockpit,mvollmer/cockpit,cockpituous/cockpit,SotolitoLabs/cockpit,andreasn/cockpit,moraleslazaro/cockpit,deryni/cockpit,deryni/cockpit,martinpitt/cockpit,andreasn/cockpit,deryni/cockpit,stefwalter/cockpit,deryni/cockpit,SotolitoLabs/cockpit,garrett/cockpit,mareklibra/cockpit,deryni/cockpit,garrett/cockpit,moraleslazaro/cockpit,mvollmer/cockpit,stefwalter/cockpit,cockpituous/cockpit,andreasn/cockpit