bots: Don't fail on existing persistent journal directory in debian.setup
bots: Don't fail on existing persistent journal directory in debian.setup

Apparently Ubuntu is now switching to persistent journal by default.

Fixes #8887
Closes #8910

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