Gateway. Enable helm templating in affinity section using tpl

[arturmkr]

Currently, .Values.affinity is rendered using toYaml, which does not evaluate Helm templates like {{ .Release.Name }}. This makes it impossible to dynamically configure affinity/anti-affinity rules in values files, especially in GitOps workflows (e.g., ArgoCD) or reusable Helm charts.

affinity:
  podAntiAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
      - labelSelector:
          matchExpressions:
            - key: app.kubernetes.io/instance
              operator: In
              values:
                - "{{ .Release.Name }}"
        topologyKey: "kubernetes.io/hostname"

[nineinchnick]

Can you add the example from the PR description to https://github.com/trinodb/charts/blob/main/tests/trino/test-values.yaml just to make sure the chart renders correctly?