Remove ci: sev label and details from ci-sev.md tempalte (#100504)
We don't want to add the label automatically: this way we can limit CI SEV creation to people with write permissions only.
Also remove `details` section as it's not really filled by people.
Fixes https://github.com/pytorch/pytorch/issues/100143
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100504
Approved by: https://github.com/clee2000, https://github.com/huydhn
