fix: AttributeError 'Build' object has no attribute 'git_sha'

[github-actions[bot]]

Original issue description

```python def __init__(self, package_name: str, package_path: str): self.package_name = package_name self.package_path = package_path try: self.repo = Repo(self.package_path, search_parent_directories=True) self.git_sha = self.repo.commit().hexsha self.git_url = self.repo.remote("origin").url except InvalidGitRepositoryError: logger.debug("[magenta]Not a git repository") ``` `self.git_sha` and `self.git_url` are not initialised as `None`.

closes #254