vmm-tests: correctly request vhost dependency, update mapping

[chris-oo]

This seemed to have been merged after another refactor, but this correctly expresses the dependency used by the vhost test.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Updates the vmm vhost-user blk device test to request the OpenVMM vhost binary as an explicit artifact dependency and adjusts Flowey’s artifact→build mapping so the correct build is triggered.

Changes:

• Add an OpenVMM vhost artifact dependency to the Linux-only vhost_user_blk_device test and use the resolved artifact path at runtime.
• Update Flowey artifact selection mapping to request building openvmm_vhost when the corresponding Linux vhost artifacts are selected.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
vmm_tests/vmm_tests/tests/tests/multiarch.rs	Switch vhost binary discovery from “known path” lookup to an explicit resolved artifact dependency passed via the test macro.
flowey/flowey_lib_hvlite/src/artifact_to_build_mapping.rs	Map Linux vhost artifact selections to build.openvmm_vhost = true so the dependency is built.