Let's make sure to check why this template was added in the first place, and that removing/changing that doesn't unexpectedly break something else.

Checked in commons betalabs and also looked at the history of the file referred in the task description: https://commons.wikimedia.org/w/index.php?title=File:1895_Galbraith_%26_Co_receipt_to_WS_Hall.tif&diff=next&oldid=836620901.
Note when the Author field is filled in, everything works as expected.

1. a file uploaded via Special:UploadWizard with the following options selected:
   • select not-own work option - "This is someone else's work and is free to share"
   • you may leave the author's name blank or select "I do not know who the author is"
2. When a file is published - see this example on commons beta.
   

=={{int:filedesc}}==
{{Information
|description={{en|1=geological exhibit iridescent test1}}
|date=2014-12-14 03:29:30
|source=testsite123.org
|author=
|permission=
|other versions=
}}

=={{int:license-header}}==
{{cc-zero}}

{{Author|Unknown}}

{{Uncategorized|year=2024|month=January|day=10}}

|author= is empty and {{Author|Unknown}} is placed above the Categories section.

5. correcting manually, i.e. moving {{Author|Unknown}} to |author=, fixes the UI.

Change 990687 had a related patch set uploaded (by Cparle; author: Cparle):

[mediawiki/extensions/UploadWizard@master] For unknown author add "unknown" to information template rather than using {{Author|Unknown}}

https://gerrit.wikimedia.org/r/990687

Change 990687 merged by jenkins-bot:

[mediawiki/extensions/UploadWizard@master] For unknown author add {{Unknown}} to information template rather than using {{Author|Unknown}}

https://gerrit.wikimedia.org/r/990687

Tested on commons beta - the templace {{Unknown|author}} is added to the information template, e.g. this file on commons beta

Note the current testing (commonswiki wmf.14)for adding files without author's information resulted in this file revision: