[Bug]: responseTransformer type is getting passed as undefined for cache response handler

[VisargD]

gateway/src/handlers/handlerUtils.ts

Lines 612 to 614 in b1d34b4

	if (!!cacheResponse) {
	return createResponse(cacheResponse, undefined, true);
	}

Instead of passing undefined, fn should be passed so that responseHandler can use it to determine the final response format. This got changed recently in the plugins release