[ci] harden test stats reporting
1. Fix bug where we were uploading stats to the wrong place in s3
2. Hard error when upload_test_stats.py didn't find any stats in s3
3. Change the name of the workflow job to include the corresponding id,
to make debugging easier in the future.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/78763
Approved by: https://github.com/janeyx99, https://github.com/seemethere
