In the future, an `Access-Control-Request-Private-Network` header will be sent with
these requests, and servers must respond with `Access-Control-Allow-Private-Network`.
This will start with the next Chrome version (104), and Mozilla has marked the
standard as "worth prototyping", which often leads to final implementation.
Signed-off-by: Franklyn Tackitt <git@frank.af>
7cd29c068d