Add buildctl du diagnostics around prune - #75

Add buildctl du diagnostics around prune#75

ConnorMul wants to merge 2 commits into

useblacksmith:mainuseblacksmith/setup-docker-builder:mainfrom

ConnorMul:debug/layer-cache-pruneConnorMul/setup-docker-builder:debug/layer-cache-pruneCopy head branch name to clipboard