Remove the dependency on git ls-files from cli/build.rs

[drogus]

Description of Changes

We technically don't need to git ls-files when getting the CLI templates because when we compile the release builds we work with a clean git clone, thus it's unlikely any untracked files will be created in the templates directory.

API and ABI breaking changes

None

Expected complexity level and risk

1

Testing

• [x] I've manually checked that the init command still generates the templates properly