Describe the bug
SteamVR won't launch due to vrcompositor-launcher trying to use pkexec under flatpak

To Reproduce
Steps to reproduce the behavior:

1. Launch SteamVR and monitor terminal outputs for obvious error.

Expected behavior
be able to launch vrcompositor-launcher without pkexec or elevation issues under flatpak

System Information (please complete the following information):

• Distribution: EndeavourOS (ARCH)
• SteamVR version: 1.25.8
• Steam client version: 1684372665
• Opted into Steam client beta?: Yes
• Graphics driver version: NVIDIA 530.41.03
• Gist for SteamVR System Information: https://gist.github.com/jarrard/ab23d03004b0ee9cae9385c974403ac6

Additional context
Some output from Steam. Also it does fail to initialize SteamVR on startup, but that may be normal.

+ pkexec setcap CAP_SYS_NICE=eip /home/theriddick/.var/app/com.valvesoftware.Steam/.local/share/Steam/steamapps/common/SteamVR/bin/linux64/vrcompositor-launcher
/home/theriddick/.var/app/com.valvesoftware.Steam/.local/share/Steam/steamapps/common/SteamVR/bin/vrstartup.sh: line 39: pkexec: command not found
++ getcap /home/theriddick/.var/app/com.valvesoftware.Steam/.local/share/Steam/steamapps/common/SteamVR/bin/linux64/vrcompositor-launcher
+ [[ '' == *\c\a\p\_\s\y\s\_\n\i\c\e* ]]
+ pErr 'Error: setcap of vrcompositor-launcher failed.'
++ date
+ echo 'Fri May 19 12:48:39 ACST 2023 - Error: setcap of vrcompositor-launcher failed.'
+ return 1
+ '[' 1 '!=' 0 ']'
+ /usr/bin/zenity --no-wrap --info '--text=SteamVR setup is incomplete, some features might be missing. See /tmp/SteamVRLauncherSetup.log for details.'