chore: Mark disable_prompt_cache as deprecated for endpoint creation (#189)

Author: blainekasten

openapi.yaml

@@ -9533,8 +9533,9 @@ components:
           $ref: '#/components/schemas/Autoscaling'
           description: Configuration for automatic scaling of the endpoint
         disable_prompt_cache:
+          deprecated: true
           type: boolean
-          description: Whether to disable the prompt cache for this endpoint
+          description: This parameter is deprecated and no longer has any effect.
           default: false
         disable_speculative_decoding:
           type: boolean