Removing .github/scale-config.yml, now this repo is using the config in test-infra (#84753)
[As communicated internally](https://fb.workplace.com/groups/pytorch.dev/permalink/1189033455008466/), all repositories now rely on a single scale-config.yml that is on pytorch/test-infra. As such this file is no longer used and to avoid confusion it is better to remove it.
Here is a short summary of the announcement:
> [As previously announced](https://fb.workplace.com/groups/pytorch.dev/permalink/1173939633184515/), the scale-config.yml file in each repository for the pytorch/ organization is now not being used to control GHA runners. On its place, [the file with same path on test-infra](https://github.com/pytorch/test-infra/blob/main/.github/scale-config.yml) repository is controlling and enabling runners. If you feel the need for new runners, or change settings for current ones, feel free to submit a PR with required changes on the former file.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/84753
Approved by: https://github.com/janeyx99, https://github.com/seemethere
