Terrascan with Private Repo and `sarif_upload` Enabled

[jrmash]

I'm encountering an error when using this action in a private repository with the sarif_upload feature enabled:

| Generating SARIF file
| 2021-11-10T23:43:09.047Z      error   utils/file.go:29        file <repo>.git does not exist.
| 2021-11-10T23:43:09.049Z      error   utils/file.go:29        file <repo>.git does not exist.
| 2021-11-10T23:43:09.050Z      error   utils/file.go:29        file <repo>.git does not exist.
| 2021-11-10T23:43:09.052Z      error   utils/file.go:29        file <repo>.git does not exist.
| 2021-11-10T23:43:09.053Z      error   utils/file.go:29        file <repo>.git does not exist.

The configuration is the same as the example usage, with the following two differences:

policy_type: all
scm_token: ${{ secrets.GITHUB_TOKEN }}