[DOCS] Install guide requires Kubernetes 1.37, but CI tests 1.35 with beta APIs enabled #3211

📋 Prerequisites

• I have searched the existing issues to avoid creating a duplicate (kagent and kagent-dev/website, open and closed; related: [DOCS] Install guide and Substrate chart still require certificates.k8s.io/v1beta1, which 1.0.0-alpha8 does not need on Kubernetes 1.37 #3083, docs: drop certificates.k8s.io/v1beta1 requirement from 1.x install guide website#578)
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📝 Issue Description

The install guide asks for Kubernetes 1.37 or later with no API server changes. But Version support says CI tests 1.35, and CI's kind cluster turns on the beta certificate APIs (Makefile L52, kind-config.yaml L22-30). So the documented setup isn't the one CI tests, unless I'm missing a test somewhere.

Which setup is the supported one? It matters for managed clusters such as EKS, which can't enable beta APIs. For what it's worth, 1.37 without them works for me (v1.0.0-alpha11 on kind and on EKS 1.37).

✅ Suggested Content or Change

Either move CI to kind 1.37 without the feature gates (Version support would follow, since it reads KIND_IMAGE_VERSION), or note on Version support that CI runs 1.35 with the beta APIs enabled.

🙋 Willing to Contribute?

• I am willing to submit a PR for this documentation update