Create Windows 1903/1909 autoscaler for gitlab-org/gitlab-runner project

Overview

In gitlab-org/gitlab-runner#4396 (closed) we need to add support for Windows 1903 and Windows 1909 in gitlab-org/gitlab-runner#6212 (closed) which requires us to have Windows Server 1903/1909 machines available for us so we are able to build 1903/1909 based images, something similar to the 1809 and 1803 machines.

Proposal

• Install autoscaler on a Windows machines.
  • This should probably belong in the same project as the Windows Shared Runners are.
  • We can reuse https://ops.gitlab.net/gitlab-com/gl-infra/ci-infrastructure-windows to provision/manage the Runner Manager machine.
  • Make sure we publish the 1903/1909 images to the same project that the autoscaler is registered
  • Configure the Runner manager to use the 1903 image
  • Configure the Runner manager to use the 1909 image
• Register two Runners specifically for https://gitlab.com/gitlab-org/gitlab-runner/-/settings/ci_cd
  • Both Runner should not run any untagged jobs
  • Windows 1903 Runner should have windows & windows-1903 tags. Windows 1909 Runner should have windows & windows-1909 tags.

Merge Request

https://ops.gitlab.net/gitlab-com/gl-infra/ci-infrastructure-windows/-/merge_requests/60