Upgrade kind to 0.18.0

[richyliu]

Upgrade kind to 0.18.0. Kind added the --all-platforms flag in version 0.17.0, which fixed an issue when running on M1 Macs (see kubernetes-sigs/kind#2957). More specifically, the following error would occur when kind was below version 0.17.0:

ERROR: failed to load image: command "docker exec --privileged -i kctf-cluster-control-plane ctr --namespace=k8s.io images import -" failed with error: exit status 1
Command Output: unpacking docker.io/kind/challenge:a18f087353a84c49aa50adc4ea421b9306781d891474320af1b360f4eda7e410 (sha256:17db2fe7f1a0c2e4b8f07d1057035fc374cdd2bafbc072fcff806a8d25f4faa9)...ctr: content digest sha256:8b34c7b1e0fda6ca91b1714d298b19dbb7427cf85a00150fc059b6759f1a8515: not found
[E] command returned 1

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