Refactor: Github Service (#6580)

Co-authored-by: Engel Nyst <enyst@users.noreply.github.com>

openhands/server/types.py

@@ -42,3 +42,15 @@ class LLMAuthenticationError(ValueError):
     """Raised when there is an issue with LLM authentication."""
 
     pass
+
+
+class GhAuthenticationError(ValueError):
+    """Raised when there is an issue with LLM authentication."""
+
+    pass
+
+
+class GHUnknownException(ValueError):
+    """Raised when there is an issue with LLM authentication."""
+
+    pass