News page: Signature assignment missing for uploads done with tag2upload

The signature assignment done by distro tracker is missing on the news page if an upload is done using tag2upload. Here are two examples showing this:

1. Sponsored upload: https://tracker.debian.org/news/1666261/accepted-autolog-0421-3-source-into-unstable/
2. Non-sponsored upload: https://tracker.debian.org/news/1664139/accepted-ngrep-147ds1-7-source-into-unstable/

Neither news page has a "Signed by:" header as it is the case for dput based uploads, like e. g. https://tracker.debian.org/news/1617350/accepted-dnstwist-020250130-1-source-into-unstable/.