[ethernet] Add LwIPLock to get_ip_addresses() on RP2040

localIP() reads netif->ip_addr which can be mutated by DHCP
callbacks from IRQ context. Lock for consistency since this is
called from API responses, not just hot-loop polling.

esphome/components/ethernet/ethernet_component_rp2040.cpp

@@ -180,6 +180,7 @@ void EthernetComponent::dump_config() {
 network::IPAddresses EthernetComponent::get_ip_addresses() {
   network::IPAddresses addresses;
   if (this->eth_ != nullptr) {
+    LwIPLock lock;
     addresses[0] = network::IPAddress(this->eth_->localIP());
   }
   return addresses;