test: Fix page switching in check-packages
test: Fix page switching in check-packages

Don't assume that the previous playground frame is still present after
page reloading. `switch_to_frame(playground/pkgs)` often silently fails
if it's not, and `#reload` is then not visible.

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