Update Cilium to v1.15.1

[ntimo]

Is your feature request related to a problem? Please describe.
Please update cilium to 1.15.1

https://github.com/cilium/cilium/releases/tag/v1.15.1

Describe the solution you'd like
Cilium that is bundled with rke2 should be updated

[mgfritch]

We recently bumped the version to v1.15.0 (#5354), but that introduced a regression where veth devices were incorrectly getting classified as native devices

[aganesh-suse]

Validated on master branch with commit 2bb7020

Environment Details

Infrastructure

• Cloud
• Hosted

Node(s) CPU architecture, OS, and Version:

$ cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.2 LTS"

$ uname -m
x86_64

Cluster Configuration:

HA : 3 server / 1 agent

or

1 server/ 1 agent

Config.yaml:

token: xxxx
write-kubeconfig-mode: "0644"
node-external-ip: 1.1.1.1
cni: cilium

Helm chart config to add in manifest folder

apiVersion: helm.cattle.io/v1
kind: HelmChartConfig
metadata:
  name: rke2-cilium
  namespace: kube-system
spec:
  valuesContent: |-
    kubeProxyReplacement: true
    k8sServiceHost: <control_plane_ip_alias_kube_api_server_ip>
    k8sServicePort: 6443
    cni:
      chainingMode: "none"

    encryption:
      enabled: true
      type: wireguard

Testing Steps

1. Copy config.yaml

$ sudo mkdir -p /etc/rancher/rke2 && sudo cp config.yaml /etc/rancher/rke2

Copy helm chart config into manifest folder: /var/lib/rancher/rke2/server/manifests

2. Install RKE2

curl -sfL https://get.rke2.io | sudo INSTALL_RKE2_COMMIT='2bb7020162174863547a0b4773b74acf6fdab71c' INSTALL_RKE2_TYPE='server' INSTALL_RKE2_METHOD=tar sh -

3. Start the RKE2 service

$ sudo systemctl enable --now rke2-server
or 
$ sudo systemctl enable --now rke2-agent

4. Check the cilium image version is v1.15.1:

$ POD_NAME=$(/var/lib/rancher/rke2/bin/kubectl --kubeconfig /etc/rancher/rke2/rke2.yaml get pods -n kube-system | grep -i cilium | grep -v helm | awk '{print $1}' | head -n 1)
$/var/lib/rancher/rke2/bin/kubectl --kubeconfig /etc/rancher/rke2/rke2.yaml get pod/"${POD_NAME}" -n kube-system -o yaml | grep -i image

Validation Results:

• rke2 version used for validation:

$ rke2 -v
rke2 version v1.29.2-rc1+rke2r1 (2bb7020162174863547a0b4773b74acf6fdab71c)
go version go1.21.7 X:boringcrypto

$ /var/lib/rancher/rke2/bin/kubectl --kubeconfig /etc/rancher/rke2/rke2.yaml get pod/cilium-fdzv9 -n kube-system -o yaml | grep -i image
  image: rancher/mirrored-cilium-cilium:v1.15.1