Add improvements to scheduler and kojidistrepo jobs

• mount /staging/ directory to store buildlists
• reposync src directory
• Add --allow-missing-signatures --noinherit --split-debuginfo to koji dist-repo
• Remove --gpgcheck from reposync
• Fix RuntimeError: dictionary changed size during iteration created by the while loop in scheluder script
• Add more logs to scheduler script
• Remove datacenters from scheduler nomad definition
• Increase the cpu allocation
• Install diffutils
• Rename src/Packages directory to source/SRPMS
• create a /debug dir per arch
• Download the debuginfo packages to the /debug dir
• Create a /os directory per arch with the Packages and repodata inside