replace shell execs to git cli with usage of https://github.com/go-git/go-git

[michaeljguarino]

Use Case

We're currently manually shelling into the git cli when we can actually use a low-level git library to perform equivalent operations with more type safety. We should gradually refactor the code to do this where possible.

Ideas of Implementation

Sequential implementation

---

Message from the maintainers:

Excited about this feature? Give it a 👍. We factor engagement into prioritization.