hydra-zen multirun on Windows

[mctierney-mitll]

Issue

When running MaDDG on Windows and attempting a multirun, hydra-zen tries to automatically create new folders with a specific date/time naming format. This format is not compatible with Windows.

Proposed Fix

Confirm that this is indeed a Windows-specific problem. At the points where multirun is called, do an OS check and override hydra-zen's default naming structure if running on Windows.

[mctierney-mitll]

Adding onto this issue, submitit just isn't supported on Windows at all. We should add an OS check if users pass in a submitit config and just raise an exception if it's Windows. The exception thrown naturally by submitit is not helpful at all.

Also, I've found a good workaround for the hydra-zen filename problem. Will create a branch and PR as soon as the outstanding GitHub Actions PR is merged in.