Add Debian forky into deb.torproject.org releases

Steps to reproduce

1. Setup a Debian forky or sid system.
2. Try to install tor using deb.torproject.org. Example procedure.

What is the current bug behavior?

Currently, the package is not installed as the forky release is missing in the upstream repository.

Example output from an affected pipeline:

+ apt-get update
Hit:1 http://deb.debian.org/debian sid InRelease
Ign:2 https://deb.torproject.org/torproject.org forky InRelease
Err:3 https://deb.torproject.org/torproject.org forky Release
  404  Not Found [IP: 2620:7:6002:0:466:39ff:fe7f:1826 443]
Reading package lists...
E: The repository 'https://deb.torproject.org/torproject.org forky Release' does not have a Release file.

What is the expected correct behavior?

A tor package is expected to be available for Debian forky.

When did this start?

This was detected today in the pipeline, caused by the use of debian:sid container image, which seems to point the forky release, since trixie was released on August 9th.

From the affected pipeline:

$ ./test/scripts/install-tor.sh
+ source /etc/os-release
++ PRETTY_NAME='Debian GNU/Linux forky/sid'
++ NAME='Debian GNU/Linux'
++ VERSION_CODENAME=forky
++ ID=debian
++ HOME_URL=https://www.debian.org/
++ SUPPORT_URL=https://www.debian.org/support
++ BUG_REPORT_URL=https://bugs.debian.org/
+ cat
+ tee /etc/apt/sources.list.d/tor.list
deb     [signed-by=/usr/share/keyrings/deb.torproject.org-keyring.gpg] https://deb.torproject.org/torproject.org forky main
deb-src [signed-by=/usr/share/keyrings/deb.torproject.org-keyring.gpg] https://deb.torproject.org/torproject.org forky main

Relevant logs and/or screenshots

This can be fixed by including Debian forky into deb.torproject.org's supported releases.