Allow VM template to be configurable in platform=none job

Description

This work is around making the golden image template that is used in the WMCO platform=none job configurable so we can test different OS versions and setups as needed in CI (example: image with containerd as the only runtime in release-4.11+) .

Engineering Details

Changes will be required in release repo to resolve the TODO in the upi-vsphere scripts.

Acceptance Criteria

• platform=none job reads VM template from env var
•  default VM template is WS2022 without Docker: windows-golden-images/windows-server-2022-template