fix: improve Wayland detection and environment setup

[omarionnn]

Overview This PR fixes the Wayland detection and environment setup issues when launching browsers through xdg-open in VS Code.

Issue When running xdg-open commands from VS Code's integrated terminal under Wayland sessions, users encounter the error: "Failed to open Wayland display, fallback to X11"

Fixes #229096

Changes

• Fixed Wayland socket path detection by using correct XDG_RUNTIME_DIR path
• Added proper GDK_BACKEND environment setup
• Added Wayland-specific environment variables for browser compatibility
• Maintained X11 fallback when Wayland is not available

Testing Notes This change requires a Linux system running a Wayland session to test. I have tested the changes on Fedora 40 with:

• Wayland session (XDG_SESSION_TYPE=wayland)
• VS Code 1.91.1
• Firefox as default browser

The fix can be verified by:

1. Running VS Code in a Wayland session
2. Opening the integrated terminal
3. Running xdg-open https://www.google.es
4. Verifying the browser opens without the "Failed to open Wayland display" error