Generated Coder SSH config contains invalid/unknown user permissions

Remote SSH connections failing on Windows because the SSH config file generated by the Coder extension has invalid file permissions.

### Error

With latest vscode plugin Remote SSH fails with the following message:

```
Bad permissions. Try removing permissions for user:
UNKNOWN\UNKNOWN (S-1-5-21-354618XXXX-405751XXXX-XXXXXXX-XXXXXXXXXX)
on file C:/Users//AppData/Roaming/coder.coder-remote/ssh/vscode--xxxxx.de.conf.

Bad owner or permissions on
C:\Users\\AppData\Roaming\coder.coder-remote\ssh\vscode--coder.zugang
```

### Workaround

Downgrading the Coder VS Code extension to version 1.15.2 resolves the issue for me.

With version 1.15.2, I can use the Coder-generated SSH configuration directly from my normal SSH config file, and VS Code Remote SSH connects successfully.