wsl2 native systemd doesn't run the user units

[farcaller]

Bug description

If the native systemd support is enabled, the user unit files are ignored.

To Reproduce

Steps to reproduce the behavior:
at e9e8d01, add a systemd unit to the user's directory (~/.config/systemd/user/) and enable it. Restart the wsl.

Expected behavior
The service starts.

Logs

With native support disabled:

$ systemctl list-unit-files --user --state=enabled
UNIT FILE                      STATE   PRESET
auto-fix-vscode-server.service enabled enabled
nixos-activation.service       enabled enabled
ssh-agent.service              enabled enabled
dbus.socket                    enabled enabled

4 unit files listed.

With native support enabled:

$ systemctl list-unit-files --user --state=enabled
Failed to connect to bus: No such file or directory

$ ps aux|grep ssh
nixos        507  0.0  0.0 222452  2516 pts/1    S+   10:45   0:00 /nix/store/86bp03jkmsl6f92w0yzg4s59g5mhxwmy-gnugrep-3.7/bin/grep --color=auto ssh

[psmf]

After some research, just providing /bin/login was sufficient for me to get properly setup user systemd services. PR #169 provisions the /bin/login symlink when native systemd is enabled.

[nzbr]

This should have been fixed by #169. Feel free to re-open if the problem persists