[undo-init] Change repo_type to local-ignore (#211)

# Exercise Review

## Exercise Discussion

Fixes an issue with undo-init exercise #179 

## Checklist

- [ ] If you require a new remote repository on the `Git-Mastery`
organization, have you [created a
request](https://github.com/git-mastery/exercises/issues/new?template=request_exercise_repository.md)
for it?
- [ ] Have you written unit tests using
[`repo-smith`](https://github.com/git-mastery/repo-smith) to validate
the exercise grading scheme?
- [X] Have you tested your changes using the instructions posted?
- [X] Have you verified that this exercise does not already exist or is
not currently in review?
- [ ] Did you introduce a new grading mechanism that should belong to
[`git-autograder`](https://github.com/git-mastery/git-autograder)?
- [ ] Did you introduce a new dependency that should belong to
[`app`](https://github.com/git-mastery/app)?

Author: jovnc

undo_init/.gitmastery-exercise.json

@@ -7,7 +7,7 @@
   "requires_github": false,
   "base_files": {},
   "exercise_repo": {
-    "repo_type": "local",
+    "repo_type": "local-ignore",
     "repo_name": "my-notes",
     "repo_title": null,
     "create_fork": null,