Steam is killed with no error message when steam runtime launch service is ran

Running steam using `flatpak run` I get

```
steam.sh[2]: Restarting Steam by request...
steam.sh[2]: Running Steam on org.freedesktop.platform 23.08 64-bit
steam.sh[2]: STEAM_RUNTIME has been set by the user to: /home/steven/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/steam-runtime
setup.sh[200]: Steam runtime environment up-to-date!
steam.sh[2]: Steam client's requirements are satisfied
tid(234) burning pthread_key_t == 0 so we never use it
[2024-02-29 18:22:10] Startup - updater built Feb 29 2024 00:39:10
[2024-02-29 18:22:10] Startup - Steam Client launched with: '/home/steven/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/steam' '-no-cef-sandbox'
02/29 18:22:10 Init: Installing breakpad exception handler for appid(steam)/version(1709168962)/tid(234)
[2024-02-29 18:22:10] Loading cached metrics from disk (/home/steven/.var/app/com.valvesoftware.Steam/.local/share/Steam/package/steam_client_metrics.bin)
[2024-02-29 18:22:10] Using the following download hosts for Public, Realm steamglobal
[2024-02-29 18:22:10] 1. https://client-update.akamai.steamstatic.com, /, Realm 'steamglobal', weight was 1000, source = 'update_hosts_cached.vdf'
[2024-02-29 18:22:10] 2. https://cdn.cloudflare.steamstatic.com, /client/, Realm 'steamglobal', weight was 1, source = 'update_hosts_cached.vdf'
[2024-02-29 18:22:10] 3. https://cdn.steamstatic.com, /client/, Realm 'steamglobal', weight was 1, source = 'baked in'
[2024-02-29 18:22:10] Verifying installation...
[2024-02-29 18:22:10] Verification complete
UpdateUI: skip show logo
Steam logging initialized: directory: /home/steven/.var/app/com.valvesoftware.Steam/.local/share/Steam/logs

XRRGetOutputInfo Workaround: initialized with override: 0 real: 0xedd0a8f0
XRRGetCrtcInfo Workaround: initialized with override: 0 real: 0xedd091c0
steamwebhelper.sh[267]: === Thu 29 Feb 2024 18:22:10 AEDT ===
steamwebhelper.sh[267]: Starting steamwebhelper under bootstrap sniper steam runtime at /home/steven/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_64/steam-runtime-sniper
CAppInfoCacheReadFromDiskThread took 111 milliseconds to initialize
Steam Runtime Launch Service: starting steam-runtime-launcher-service
Steam Runtime Launch Service: steam-runtime-launcher-service is running pid 365
bus_name=com.steampowered.PressureVessel.LaunchAlongsideSteam
```
and then immediately after this the process is killed and Steam doesn't launch, with no error message in the terminal. Where should I look in the log files to debug this issue?

Start with the Steam logs in /home/steven/.var/app/com.valvesoftware.Steam/.local/share/Steam/logs and the terminal output around Steam Runtime Launch Service startup. Check the steamwebhelper and runtime launch-service entries immediately before termination. Done means identifying an actionable error or documenting where the process exits without one.

Written by the indexing model from the issue text.