Error handling needed for repositories that have been deleted

Example: https://github.com/anaconda-platform/transformers-feedstock

Exception('ERROR: Repo has moved, and there is no redirection! 404 returned, not 301. Resetting Collection!')

`
Traceback (most recent call last): File "/opt/venv/lib/python3.9/site-packages/celery/app/trace.py", line 451, in trace_task R = retval = fun(*args, **kwargs) File "/opt/venv/lib/python3.9/site-packages/celery/app/trace.py", line 734, in protected_call return self.run(*args, **kwargs) File "/augur/augur/tasks/github/detect_move/tasks.py", line 27, in detect_github_repo_move_core ping_github_for_repo_move(session, key_auth, repo, logger) File "/augur/augur/tasks/github/detect_move/core.py", line 118, in ping_github_for_repo_move raise Exception("ERROR: Repo has moved, and there is no redirection! 404 returned, not 301. Resetting Collection!") Exception: ERROR: Repo has moved, and there is no redirection! 404 returned, not 301. Resetting Collection!

`