[Bug]: SdkHttpResponse.contentTypes? can be empty array

[archerzz]

Describe the bug

minor

SdkHttpResponse.contentTypes is an optional array:

typespec-azure/packages/typespec-client-generator-core/src/interfaces.ts

Lines 435 to 440 in d30db5b

	export interface SdkHttpResponse extends SdkServiceResponse {
	__raw: HttpOperationResponse;
	kind: "http";
	contentTypes?: string[];
	defaultContentType?: string;
	}

So it would be better to either a non-empty array or undefined, but not an empty array.

Reproduction

Try to parse a spec like https://github.com/Azure/cadl-ranch/blob/main/packages/cadl-ranch-specs/http/authentication/http/custom/main.tsp

You'll find the contentTypes is an empty array.

Checklist

• Follow our Code of Conduct
• Check that this issue is about the Azure libraries for typespec. For bug in the typespec language or core libraries file it in the TypeSpec repo
• Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
• The provided reproduction is a minimal reproducible example of the bug.

[iscai-msft]

good point, let me fix this