Support Windows Nanoserver-based build images

Description

This issue is #27713 (closed) rephrased as a feature request.

Windows Nanoserver-based container images are more lightweight than other Windows images and therefore help reduce network and storage pressure on the system.

I therefore propose to add support for using Windows Nanoserver-based build images in the docker-windows executor.

Proposal

Make the following job succeed:

use-nanoserver-image:
  stage: test
  tags: [WINDOWS-DOCKER-1809]
  image: mcr.microsoft.com/powershell:nanoserver-1809
  script:
    - echo Hi

(Note that using mcr.microsoft.com/windows/nanoserver:1809 directly is out of scope, because this image does not contain PowerShell)

Links to related issues and merge requests / references

• #27713 (closed)