Fix missing digest input and update attestation

[Root-DE]

This Pull Request:

• adds the digest input
• Fix: attestation generation (adds the missing subjects)
• remove already set env variables co-authored-by @jobroe10

We made these changes while using the container workflow and realising it was not fully working

[Root-DE]

@ianlewis what do you think?

[ianlewis]

I think pretty much all of the issues we were addressing in this PR have been addressed elsewhere. Feel free to re-open and update the PR if you think there are still changes that need to be made.