refactor: update runtime configuration in values.yaml

- Changed the structure of the `runtimes` section in `values.yaml` to use a key-value format for better clarity and organization, replacing the previous list format.
- Updated the names of the runtimes to be keys, improving readability and maintainability of the configuration.

values.yaml

@@ -211,10 +211,10 @@ global:
 # Each runtime inherits settings from `global` (resources, env, probes, autoscaling)
 # unless overridden here.
 runtimes:
-  - name: "basic"
+  basic:
     # Replicas for this runtime. Replaces the old replicaCount.
     replicas: 1
-  - name: "xgboost"
+  xgboost:
     replicas: 1
 
 # -----------------------------------------------------------------------------