[http-specs][bug] API doesn't follow runtime behavior

[msyyc]

typespec/packages/http-specs/specs/documentation/main.tsp

Lines 85 to 96 in 7157290

	@scenarioDoc("""
	Test bullet points in model and enum documentation.
	Expected input:
	```json
	{
	"prop": "Simple"
	}
	```
	""")
	@post
	@route("/bullet-points/model")
	op bulletPointsModel(input: BulletPointsModel): NoContentResponse;

doesn't follow runtime behavior of

typespec/packages/http-specs/specs/documentation/mockapi.ts

Lines 37 to 42 in 7157290

	Scenarios.Documentation_Lists_bulletPointsModel = createPostServerTests(
	"/documentation/lists/bullet-points/model",
	{
	prop: "Simple",
	},
	);

The related file shall make the following 2 fixes

1. change response type of op bulletPointsModel to OkResponse
2. update expected request of op bulletPointsModel to

{
  "input": {"prop": "Simple"}
}

NOTE: please fix main.tsp and mockapi.ts at the same time.

[msyyc]

After this issue resolved, we could reopen test case for https://github.com/microsoft/typespec/pull/8927/files#diff-8a1b7d09be7a2e3e5524ec956eac181cf0bade458ce3cac4f65d240fa5217e64