[BUG] Spec For Get Keys of Azure Functions

### API Spec link

https://learn.microsoft.com/en-us/rest/api/appservice/web-apps/list-function-keys?view=rest-appservice-2024-04-01

### API Spec version

2024-04-01

### Describe the bug

Hi Team,
The Spec for Get Keys of Azure function is not aligning with the response. It seems to be wrong in the documentation too.
When we call the API the response is in the form of Key Value Pair

I have updated the Spec here and PR is up for review - https://github.com/Azure/azure-rest-api-specs/pull/33565 , if someone can take a look into it. I am more than happy to make the required changes.


### Expected behavior

The response should be in the form of key value Pair.
Fixed in the above PR

### Actual behavior

Response is coming in the form **StringDictionary**

### Reproduction Steps

Call the API providing the name of function.
Sample screenshot attached

### Environment

_No response_

Start by reviewing the linked Azure REST API specification for List Function Keys and PR 33565, then compare its response schema with the documented 2024-04-01 API response. Done means the specification represents the response as key-value pairs rather than StringDictionary and the proposed PR is resolved.

Written by the indexing model from the issue text.