Docs: fix kubectl command

[Kavinjsir]

Description

Docs: fix the kubectl command shown in the homepage.

Motivation

Ever since: kubernetes/kubectl@e0816cb, the --short flag has been removed. Running commands with this flag now results in an error:

❯ kubectl version --client
Client Version: v1.31.0
Kustomize Version: v5.4.2
❯ kubectl version --short --client
error: unknown flag: --short
See 'kubectl version --help' for usage.

[stormqueen1990]

Thank you, @Kavinjsir!

/lgtm
/assign @koba1t
for maintainer review

[koba1t]

Thanks @Kavinjsir
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Kavinjsir, koba1t

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