feat: use current checked out commit hash in UploadMetadata

[adriencaccia]

No description provided.

[adriencaccia]

@art049 you can review the aggregated file changes directly, I will squash in a single commit at the end

[art049]

As discussed, we should replace commit_hash with the commit hash from libgit and remove this actual_commit_hash.
The rest of the logic to find the "actual" commit will be handled on our backend.