doctl fail to install serverless when using docker

I am trying to use the **docker** version of doctl and:

1. sadly the image was created without serverless support already installed (why?) (also mentioned here #1559)
2. it fails when running `docker run --rm -it --env=DIGITALOCEAN_ACCESS_TOKEN=??? digitalocean/doctl serverless install`. Error is: `stat /root/.config/doctl: no such file or directory`
3. unable to access container's shell to check for the correct path and fix it with the install option `-c`

**Environment:**

- doctl version:
```
REPOSITORY TAG IMAGE ID CREATED SIZE
digitalocean/doctl latest 02672a76bc47 2 hours ago 50MB

doctl version 1.121.0-release
Git commit hash: a24ecf6c
```
- OS: linux debian
- Installation method: docker