DNS broken for Linux Sandbox when using systemd-resolved stub resolver #5027

Describe the bug

Currently, when running sandbox in a Linux host with systemd-resolvd stub resolver, the sandbox shares the host's /etc/resolv.conf, which sends DNS to nameserver 127.0.0.53.

However, this address is not reachable from inside the sandbox, as it's a loopback address from the host. This behaviour leads to broken DNS resolution from inside the sandbox.

Affected version

GitHub Copilot CLI 1.0.90

Steps to reproduce the behavior

On a machine which use systemd-resolved stub DNS resolver

1. Run copilot
2. Ask it to send a test request to any address, e.g: example.com

Expected behavior

DNS should work with sandbox in Linux box using systemd-resolved stub resolver

Additional context

No response