Create new repo_type to handle undo-init exercise

Author: jovnc

src/git_autograder/exercise.py

@@ -66,7 +66,7 @@ def __init__(
             # is the purpose of handling the exception where we can display an error on
             # their end.
             self.repo: GitAutograderRepoBase
-            if self.config.exercise_repo.repo_type == "ignore":
+            if self.config.exercise_repo.repo_type == "ignore" or self.config.exercise_repo.repo_type == "local-ignore":
                 self.repo = NullGitAutograderRepo()
             else:
                 self.repo = GitAutograderRepo(

src/git_autograder/exercise_config.py

@@ -8,7 +8,7 @@
 class ExerciseConfig:
     @dataclass
     class ExerciseRepoConfig:
-        repo_type: Literal["local", "remote", "ignore"]
+        repo_type: Literal["local", "remote", "ignore", "local-ignore"]
         repo_name: str
         repo_title: Optional[str]
         create_fork: Optional[bool]