fix: use core-test.fuellabs.net for dnsaddr resolution

Author: rymnc

crates/services/p2p/src/dnsaddr_resolution.rs

@@ -96,7 +96,7 @@ mod tests {
         // when
         // run a `dig +short txt _dnsaddr.mainnet.fuel.network` to get the TXT records
         let multiaddrs = resolver
-            .lookup_dnsaddr("mainnet.fuel.network")
+            .lookup_dnsaddr("core-test.fuellabs.net")
             .await
             .unwrap();
         // then