chore(flux): update image renovate 1.19.0 → 1.20.0 (#33295)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [renovate](https://truecharts.org/charts/stable/renovate)
([source](https://redirect.github.com/truecharts/charts/tree/HEAD/charts/stable/renovate))
| minor | `1.19.0` -> `1.20.0` |

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This PR has been generated by [Renovate
Bot](https://redirect.github.com/renovatebot/renovate).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzOS4xOTkuMSIsInVwZGF0ZWRJblZlciI6IjM5LjE5OS4xIiwidGFyZ2V0QnJhbmNoIjoibWFzdGVyIiwibGFiZWxzIjpbImF1dG9tZXJnZSIsInJlbm92YXRlL2NvbnRhaW5lciIsInR5cGUvbWlub3IiXX0=-->

clusters/main/kubernetes/apps/renovate/app/helm-release.yaml

@@ -10,7 +10,7 @@ spec:
   chart:
     spec:
       chart: renovate
-      version: 1.19.0
+      version: 1.20.0
       sourceRef:
         kind: HelmRepository
         name: truecharts