[Error] Containers with init system loose network state

**Describe the bug**
When the network configuration changes, containers with an init system will keep the old one, which will in some cases prevent applications in the container from making DNS requests. It also means that applications will not follow the DNS of a VPN after it gets enabled.

**To Reproduce**
- Start a distrobox with systemd enabled
- Activate a VPN, for example through NetworkManager
- Change to a different wifi or enable a VPN
- `ping github.com`
- Dns Request is routed to the dns server of the last network

**Expected behavior**
The new dns configuration is used inside the container.

**Desktop**
- podman 5.4.2
- distrobox 1.8.1.2
- Vanilla OS
- The official debian package on the host system

**Additional context**
This happens because the following is disabled in containers with an init system:
https://github.com/89luca89/distrobox/blob/71cf8295fb74bb2805904cb3fb497556331ec169/distrobox-init#L2464-L2508