update status check for cosign and scaffold repo

[cpanato]

Summary

• update status check for cosign and scaffold repo, now all existing jobs are required

this is already applied, just to sync with the code automation

Fixes: sigstore/cosign#2154
Fixes: sigstore/scaffolding#289

For cosign:

for scaffold

[vaikas]

Thank you so much for doing this @cpanato !!!