Revert "Manually shard slow-gradcheck CI job to prevent timeout #83354" (#83704)
Now that https://github.com/pytorch/test-infra/pull/529 exists, we can undo the custom sharding from #83354 for slow grad check
test plan: look at logs to see if it sharded + look at time to see that its evenly distributed
Pull Request resolved: https://github.com/pytorch/pytorch/pull/83704
Approved by: https://github.com/huydhn
