### What this PR does / why we need it?
This PR adds a jinja template for the k8s configuration file, prepare
for the upcoming 4-node CI
### Does this PR introduce _any_ user-facing change?
### How was this patch tested?
- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0
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Signed-off-by: wangli <wangli858794774@gmail.com>