"cijobs" tool should be updated for Azure DevOps, or removed

Currently, the `cijobs` tool was built to work against the previous Jenkins CI system, for finding baseline builds. It should be updated to work against Azure DevOps instead.

If that is deemed to be unnecessary, then it should be removed.

Note that it would still be ideal to automatically find and download a baseline JIT compiler (and/or full dotnet or coreclr build), so the basic functionality of finding and downloading a baseline build is still very useful.