[Release-1.29] - Bump containerd to v1.7.26

[brandond]

We're bumping to containerd v2.0.3 on other branches, on this branch we just need latest 1.7.

No bugs to fix, just a version bump.

• Fallback to default registry endpoint is broken when using "*" wildcard mirror in registries.yaml with containerd 2.0 #11857

[mdrahman-suse]

Validation on release-1.29 branch with commit 288efc5

Latest 1.7 https://github.com/containerd/containerd/releases/tag/v1.7.26

~> k3s -v
k3s version v1.29.14+k3s-288efc52 (288efc52)
go version go1.22.12

~> kubectl get node -o yaml | grep containerd -A1
      containerRuntimeVersion: containerd://1.7.26-k3s1
      kernelVersion: 5.14.21-150500.55.44-default