Update Accept header for JSON modules with network imports #20866
Description
The HTML spec is being updated to use the appropriate fetch destination for JSON modules: whatwg/html#9486, whatwg/fetch#1691
As far as I can tell, the only relevant different for Deno is that now JSON modules are fetched with the Accept: application/json,*/*;q=0.5 HTTP header rather than Accept: */*. My knowledge of Deno's module system is limited, so please somebody else confirm this.