chore(ci): update qemu build with optional ht

[nevermarine]

Description

Update QEMU to 10.2.2, enable AVX2 and membarrier in the QEMU build configuration, disable seccomp support, and keep HT CPU feature handling optional in VM CPU model generation.

Why do we need it, and what problem does it solve?

This PR follows the same direction as PR #2339 for the QEMU build rework, but uses optional HT handling instead of required HT in the virtualization artifact. That lets us evaluate the updated QEMU build together with a less strict CPU feature policy for migration-related behavior.

What is the expected result?

1. Build the QEMU image.
2. Verify the configure step enables AVX2 and membarrier.
3. Verify seccomp is disabled.
4. Verify generated VM CPU definitions include the ht feature with optional policy for model and discovery/features flows when HT is absent.
5. Confirm unit tests for CPU feature generation pass.

Checklist

• The code is covered by unit tests.
• e2e tests passed.
• Documentation updated according to the changes.
• Changes were tested in the Kubernetes cluster manually.

Changelog entries

section: ci
type: chore
summary: "Update QEMU build configuration and add an optional HT CPU feature variant for migration-related checks."
impact_level: low