feat(net): prepare the polling task for network interfaces

[ytakano]

Description

Previously, network interfaces were polled only by the primary core. However, polling may not occur if the primary core enters a sleep state.
This PR introduces a dedicated polling task to ensure that network interfaces are consistently polled, even when the primary core is sleeping.

Current primary core:

loop {
   poll_network_interfaces();
   sleep(); // wait interrupts forever, may not poll network interfaces.
}

Related links

How was this PR tested?

Notes for reviewers