[rocm-libraries] ROCm/rocm-libraries#4336 (commit d26a782)

[CK] MICI: Use reference repo for checkout operations

## Motivation

- Maintain a reference repo on slave nodes that speeds up any
clone/checkout operations

## Technical Details

- clone a ref repo if it does not exist
- update ref repo if it does exist
- checkout after ref repo is updated
- eliminates double clone

## Test Result

- Initial checkouts succeeded