retire games/depotdownloader?

Hi,

This port is a .NET implementation of a tool that can interact with
Steam's API and, for example, download Steam games. It was useful while
it worked with mono, but recent versions require dotnet. I gave the
most recent version 2.4.7 another go, but it errors out with:

System.TypeLoadException: Could not resolve type with token 01000034 from typeref (expected class 'System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1' in assembly 'System.Runtime, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a')

Due to changes on Valve's/Steam's end to their API, the outdated
version of depotdownloader isn't in sync with the API anymore. Trying
to download FEZ with depotdownloader 2.3.6 yields this:

Downloading depot manifest...Got CDN auth token for edge.steam-dns.top.comcast.net result: OK (expires 03/31/2023 21:13:55)
Encountered 401 for depot manifest 224762 5672754372855605298. Aborting.

We have games/steamctl which works and is written in python, so
unlikely to become completely useless like depotdownloader. We can
revisit depotdownloader if we ever get a dotnet runtime to work on
OpenBSD.

ok to send depotdownloader to the attic?