`repo-versioning` Pipeline improvements

Pipelines:

* https://dev.azure.com/azure-sdk/internal/_build?definitionId=1698
* https://dev.azure.com/azure-sdk/internal/_build?definitionId=1698

Agent machines in the pipeline have run out of space cloning the configured repos. To prevent this a couple of approaches may be taken:

1. Sparse checkout only the interesting files (`**/*.yml`?)... this could improve perf on the whole pipeline AND/OR
2. Delete a clone after the work on it has completed

Start with the Azure DevOps pipeline definition 1698 linked in the issue and inspect how configured repositories are cloned. Compare sparse checkout of **/*.yml with deleting each clone after its work completes, then use pipeline runs to confirm agent disk usage no longer fails. Done means the pipeline completes without exhausting agent space.

Written by the indexing model from the issue text.