Better error message for missing SHA256SUMS file

[janosdebugs]

Thank you for reporting an issue.

Currently, a missing SHA256SUMS file causes the following error message:

No versions detected for repository {URL}

This is not helpful and does not tell the user what to do. The error message should be more helpful, point to the GitHub Action run and/or contain the specific error cause.

OpenTofu Version

N/A

OpenTofu Configuration Files

N/A

[lplazas]

I'd be happy to work on this as a first contribution.

[cam72cam]

Thanks @lplazas, sorry it took us a bit to get to your message!