fix: add support for response header rendering for status code 204

[abhiandthetruth]

While having a spec like

"responses": {
                    "204": {
                        "description": "Success",
                        "headers": {
                            "X-Auth-Token": {
                                "description": "header containing the auth token",
                                "schema": {
                                    "type": "string"
                                }
                            }
                        }
                    },
                    "401": {
                        "description": "Unauthorized"
                    },
                    "422": {
                        "description": "Validation Error",
                        "content": {
                            "application/json": {
                                "schema": {
                                    "$ref": "#/components/schemas/HTTPValidationError"
                                }
                            }
                        }
                    }
                }

we don't get the responseheader hook in the generated clientservice since it is filtered out. Whereas according to HTTP spec(https://www.rfc-editor.org/rfc/rfc9110.html#section-15.3.5-1) and MDN docs(https://developer.mozilla.org/en-US/docs/Web/HTTP/Status#successful_responses) 204 can include headers

[abhiandthetruth]

@ferdikoomen review?

[mrlubos]

Hey @abhiandthetruth, please check out our fork, that might have what you're looking for