fix(vm): dynamic domain wait timeout

[danilrwx]

Description

Under inbound-slot contention the migration target's virt-launcher panicked with timed out waiting for domain to be defined (~240–360s) and an otherwise valid live migration failed. While a migration waits for a free inbound slot, the target had no domain defined yet, so its fixed domain-wait deadline expired.

This bumps 3p-kubevirt to v1.6.2-v12n.59, which keeps the target's domain-wait alive while the migration is held by the inbound migration limiter. The deadline is extended only by an explicit keepalive and is bounded by a hard ceiling, so ordinary requests don't reset it and a genuinely stuck target still times out.

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

Live migrations that had to queue for an inbound slot were failing by target timeout instead of proceeding once a slot freed up. Users saw valid migrations fail under contention.

What is the expected result?

Migrations that wait for an inbound slot succeed instead of failing by target timeout; existing migration e2e stays green.

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: vm
type: fix
summary: "Live migrations no longer fail by target timeout while waiting for a free inbound migration slot."