## 🐛 Bug Report The method `Repository.lookup_submodule` from `pygit2` was removed (deprecated). But the `scanner` module is still calling it causing an exception. Line: https://github.com/godaddy/tartufo/blob/345092b4b2b237c1c940d079aedf411fdc17b383/tartufo/scanner.py#L776 ## To Reproduce Scan a repository with GIT submodules. ## Expected Behavior Complete scan. ## Code Example Removing error handler exposes the actual exception: ```python3 Traceback (most recent call last): File "<string>", line 1, in <module> AttributeError: 'Repository' object has no attribute 'lookup_submodule' ``` ## Environment Any.