The code generator crashes when processing response types with undefined

[v-jiaodi]

Generate code error:

Please note the followings:

• @azure-rest/codetransparency is not in our smoke testing and we put their spec in draft pr: Verify that the library option is set to true for @azure-rest/codetransparency #3424
• to reproduce this issue, you need to first add their spec in our pr
• i take a look at the spec and I guess this issue may be from

  autorest.typescript/packages/typespec-test/test/Microsoft.CodeTransparency/spec/main.tsp

  Lines 109 to 123 in 52c97f6

  	@doc("Status code")
  	@statusCode
  	statusCode: 201;
  	@doc("The MIME content type a Cose body is application/cose, containing a CoseSign1 signature.")
  	@header("Content-Type")
  	contentType: "application/cose";
  	@doc("Location of the receipt")
  	@header("Location")
  	location?: string;
  	@doc("Receipt body in COSE format")
  	@bodyRoot
  	body: bytes;

  .
• i think for "application/cose" content type the body bytes should be generated as "binary" thing
• it's better to add this case in our modular unit test

[MaryGao]

We need to verify if our implementation works with spector cases - microsoft/typespec#8405.

[MaryGao]

De-upgrade the priority as p1 since only one service impacted.