[sgl-router] Render chat prompts with dynamo-render (#38983)

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>

experimental/sgl-router/Cargo.lock

@@ -2072,7 +2072,6 @@ dependencies = [
  "memo-map",
  "percent-encoding",
  "serde",
- "serde_json",
 ]
 
 [[package]]
@@ -3285,7 +3284,6 @@ dependencies = [
  "anyhow",
  "axum",
  "bytes",
- "chrono",
  "clap",
  "criterion",
  "dashmap",
@@ -3301,7 +3299,6 @@ dependencies = [
  "k8s-openapi",
  "kube",
  "minijinja",
- "minijinja-contrib",
  "parking_lot",
  "rand 0.8.8",
  "reqwest",