SRB2 Ubuntu PPA needs updating

[eblu]

Hey. After a bit of distro-hopping I tried to re-install SRB2 via the official Linux method on the website but following the instructions gives me this:

$ sudo add-apt-repository ppa:stjr/srb2
 [sudo] password for eblu: 
 The premiere apt repository for Sonic Robo Blast 2, a 3D Sonic the Hedgehog fangame based on a modified version of Doom Legacy. www.srb2.org
 More info: https://launchpad.net/~stjr/+archive/ubuntu/srb2
Press [ENTER] to continue or Ctrl-c to cancel adding it.

Hit:1 http://us.archive.ubuntu.com/ubuntu eoan InRelease
Hit:2 http://apt.pop-os.org/proprietary eoan InRelease
Hit:3 http://ppa.launchpad.net/libretro/stable/ubuntu eoan InRelease         
Get:4 http://us.archive.ubuntu.com/ubuntu eoan-security InRelease [97.5 kB]  
Ign:5 http://ppa.launchpad.net/stjr/srb2/ubuntu eoan InRelease                 
Get:6 http://us.archive.ubuntu.com/ubuntu eoan-updates InRelease [97.5 kB]     
Hit:7 http://ppa.launchpad.net/system76/pop/ubuntu eoan InRelease              
Get:8 http://us.archive.ubuntu.com/ubuntu eoan-backports InRelease [88.8 kB]
Err:9 http://ppa.launchpad.net/stjr/srb2/ubuntu eoan Release
  404  Not Found [IP: 91.189.95.83 80]
Reading package lists... Done                             
E: The repository 'http://ppa.launchpad.net/stjr/srb2/ubuntu eoan Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

It's pretty obvious that what's happening here is that packages aren't being built for the latest version of Ubuntu (19.10) and its derivatives. While Linux isn't exactly the highest priority in development, it would definitely help if this was fixed.