Update `Accept` header for JSON modules with network imports

[nicolo-ribaudo]

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 Node.js is that now JSON modules are fetched with the Accept: application/json,*/*;q=0.5 HTTP header rather than Accept: */*. My knowledge of Node.js' HTTP imports implementation is limited, so please somebody else confirm this.

[marco-ippolito]

I think it should not have any impact other than

node/lib/internal/modules/esm/fetch_module.js

Line 149 in 78a1570

headers: { Accept: '*/*' },

but I'll wait for more opinions