steam-runtime-tools v0.20230919.0

  * pressure-vessel:
    - Use a fully-resolved path when pointing to Vulkan drivers' and layers'
      JSON manifests, fixing broken symlinks when running under Flatpak
    - Try to avoid duplicating Vulkan drivers and layers, by marking their
      manifests with the `library_arch` parameter where appropriate.
      In particular this fixes loading of released MangoHud versions
      under Flatpak (steam-runtime#618)
  * system-info:
    - Fix an incorrect use of VA-API that can cause an assertion failure in
      debug builds of Mesa (steam-runtime-tools#117). Thanks to David Rosca
    - Fix an incorrect use of VA-API that can cause the check to fail
      with non-Mesa drivers. Thanks to Emil Velikov
    - Avoid searching ~/.local/share for Vulkan drivers twice if it
      resolves to the same path as $XDG_DATA_HOME
    - Log a warning if machine-readable output cannot be closed
    - Refactoring
  * input-monitor:
    - Fix an ongoing memory leak
  * Documentation updates
  * Tests:
    - Fix continuous-integration failure when the beta and stable scout SDKs
      currently have different versions of a library that gets bundled
      with pressure-vessel, notably GLib
    - Improve logging when testing graphics driver discovery