bots: Move openshift-prerelease to 3.10
bots: Move openshift-prerelease to 3.10

Current openshift-prerelease is at 3.9alpha3, as tagging happens rather
inconsistently. This is older than openshift (3.9 final), so move
prerelease to the latest docker tag. This is currently the 3.10
development branch. Testing that makes much more sense as it will report
regressions earlier on.

Closes #9061

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