Fix `update_pytorch_labels` workflow (#95227)
Pass in repo args now that they're required (after a recent refactor). Also changes the script to pass in the repo name instead of being hardcoded to pytorch/pytorch.
I'm guessing this wasn't noticed earlier since the workflow is only triggered when a label is created/edited/deleted
Pull Request resolved: https://github.com/pytorch/pytorch/pull/95227
Approved by: https://github.com/huydhn
