Malformed IPv6 address used in topology-update workers

What happened:

Turning on node-topology-updater crashloops on an IPv6-first cluster.

What you expected to happen:

Don't crashloop.

How to reproduce it (as minimally and precisely as possible):

Setup an IPv6 cluster (optionally dual stack, but IPv6 must have priority).

Anything else we need to know?:

https://github.com/kubernetes-sigs/node-feature-discovery/pull/1218#discussion_r1185922510

This is where the bug stems from.

E0529 21:48:11.522990       1 main.go:66] "error while running" err="failed to detect TopologyManager's policy and scope: failed to get kubelet config from configz endpoint: Get \"https://fdb5:12c1:f8cb:0:dd8f:717d:abc8:f650:10250/configz\": context deadline exceeded (Client.Timeout exceeded while awaiting headers)"

The IP address needs to have [] around the address: https://[fdb5:12c1:f8cb:0:dd8f:717d:abc8:f650]:10250/configz.

Environment:

Kubernetes version (use kubectl version): v1.29.5+k3s1
Cloud provider or hardware configuration: self hosted
OS (e.g: cat /etc/os-release): Fedora CoreOS 40.20240504.3.0
Kernel (e.g. uname -a): 6.8.8-300.fc40.x86_64
Install tools:
Network plugin and version (if this is a network-related bug): flannel
Others:

kubernetes-sigs / node-feature-discovery

Malformed IPv6 address used in topology-update workers #1727