Bug#1131109: steam-installer: package not installable on trixie

[Michał Trojnara]

I managed to diagnose and fix the issue: Something has created 
/etc/apt/apt.conf.d/99default-arch on my machine.  Deleting the file 
allowed for installing steam-installer.

I failed to identify the culprit, as the file did not belong to any 
package currently installed on my machine.

I confirm that my bug report was a false positive, but I hope this 
information helps someone experiencing a similar issue.

Best regards,
    Mike