Fix CI/CD runtime checks failing on Ubuntu 24.04

GitHub runners now use Ubuntu 24.04, which introduces two issues
affecting Electron application runtime checks:

1. AppArmor restrictions on unprivileged user namespaces
2. Outdated Mesa drivers

This commit resolves both with workarounds.

Changes:

- Disable AppArmor restrictions on unprivileged user namespaces:
  - Resolves the following error:
    ```
    [5475:1011/121711.489417:FATAL:setuid_sandbox_host.cc(158)] The SUID sandbox helper binary was found, but is not configured correctly. Rather than run without sandboxing I'm aborting now. You need to make sure that /tmp/.mount_privacv1kcOj/chrome-sandbox is owned by root and has mode 4755.
    ```
  - Related key Electron issues:
    - electron/electron#41066
    - electron/electron#42510
    - electron-userland/electron-builder#8440
- Update Mesa drivers
  - Fixes following errors:
    ```
    MESA: error: ZINK: failed to choose pdev
    glx: failed to create drisw screen
    ```
  - Installs latest Mesa drivers from Kisak PPA

.github/workflows/checks.desktop-runtime-errors.yaml

@@ -31,7 +31,7 @@ jobs:
         uses: ./.github/actions/install-imagemagick
       -
         name: Configure Ubuntu
-        if: contains(matrix.os, 'ubuntu') # macOS runner is missing Docker
+        if: contains(matrix.os, 'ubuntu')
         shell: bash
         run: |-
           sudo apt update
@@ -61,6 +61,18 @@ jobs:
 
           # Install xdotool and xprop (from x11-utils) for window title capturing
           sudo apt install -y xdotool x11-utils
+
+          # Workaround for Electron AppImage apps failing to initialize on Ubuntu 24.04 due to AppArmor restrictions
+          # Disables unprivileged user namespaces restriction to allow Electron apps to run
+          # Reference: https://github.com/electron/electron/issues/42510
+          sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0
+
+          # Workaround for Mesa driver issues on Ubuntu 24.04
+          # Installs latest Mesa drivers from Kisak PPA
+          # Reference: https://askubuntu.com/q/1516040
+          sudo add-apt-repository ppa:kisak/kisak-mesa
+          sudo apt update
+          sudo apt upgrade
       -
         name: Test
         shell: bash