feat(k8s): add k8s-health-check reusable workflow

[Codex]

Description

• Workflow: New reusable .github/workflows/k8s-health-check.yaml that validates Karpenter, Datadog (operator/cluster-agent/node-agent), DatadogAgent CR conditions, and Lacework rollouts post-apply; fails fast on missing cluster.
• Docs: Generated docs/workflows/k8s-health-check.md describing checks and usage.
• Config: Renamed Renovate baseBranchPatterns to baseBranches to align with schema.
• Release note: Removed minor-bump guidance from README.

Example usage:

health-check-dev:
  uses: DND-IT/github-workflows/.github/workflows/k8s-health-check.yaml@v3
  with:
    environment: platform-dev

Motivation and Context

Ensure prod deploys are gated on a healthy dev cluster by codifying post-apply Kubernetes checks and documenting workflow usage.

Breaking Changes

None.

How Has This Been Tested?

• I have updated at least one of the .github/workflows/_test-*.yaml to demonstrate and validate my change(s)
• I have executed pre-commit run -a on my pull request
• I have executed make gen_docs_run on my pull request

Github Conventional Commit Release

https://dnd-it.github.io/github-workflows/workflows/gh-release/