hypervisor/kubevirt: implement CPU pinning for HV=k (KubeVirt)

[zedi-pramodh]

When CPUsPinned is set on a domain config, the KubeVirt VMI spec now:

• Sets DedicatedCPUPlacement=true so the KubeVirt CPU Manager pins each vCPU to a unique physical CPU thread
• Sets CPU Requests==Limits and Memory Requests==Limits in the VMI domain resources to achieve Kubernetes Guaranteed QoS, which is required by the kubelet static CPU Manager policy to honour dedicated CPU placement

Additional changes to complete CPU pinning support for HV=k (KubeVirt):

1. pkg/kube/kubevirt-features.yaml Add CPUManager to the KubeVirt CR featureGates list so KubeVirt's CPU Manager integration is activated on fresh installs.

2. pkg/kube/kubevirt-utils.sh Update Kubevirt_migrate_feature_gates() to detect and patch in the CPUManager gate on upgrade from older EVE images. The sentinel check is updated from VideoConfig to CPUManager (the newest required gate) so the patch runs once on any image that lacks it.

3. pkg/kube/config.yaml Add cpu-manager-policy=static and cpu-manager-reconcile-period=5s to the k3s kubelet-arg list. The static policy is required by Kubernetes for exclusive (pinned) CPU allocation: pods must be in Guaranteed QoS (Requests == Limits) and the kubelet will then assign dedicated pCPUs. The reconcile period keeps the CPU Manager state in sync quickly.

4. Refactor the code in Kubevirt VM start where it is leading to infinite loop in case of error in ReplicaSet creation.

How to test and validate this PR

1. Create a VM with CPU pinning enabled.
2. Once the VM starts verify that qemu process has the affinity set using task set command.
3. Launch another VM with CPU pinning enabled even if sufficient CPUs are not available, that VM will be in Pending start state.
4. Delete VM from step2 and notice VM in steps 3 will start since it got CPU

Changelog notes

CPU Pinning support for eve-k VMs

Checklist

• I've provided a proper description
• I've added the proper documentation
• I've tested my PR on amd64 device
• I've written the test verification instructions

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 29.49%. Comparing base (2281599) to head (8958df5).
⚠️ Report is 339 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5676      +/-   ##
==========================================
+ Coverage   19.52%   29.49%   +9.96%     
==========================================
  Files          19       18       -1     
  Lines        3021     2417     -604     
==========================================
+ Hits          590      713     +123     
+ Misses       2310     1552     -758     
- Partials      121      152      +31     

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[rene]

@zedi-pramodh , LGTM, just minor things:

1. There is one valid Yetus error to fix
2. We don't add newlines between the Co-Authered-By/Signed-off-by lines, so in your commit you can just put like this:

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Pramodh Pallapothu <pramodh@zededa.com>