add delay after confirming payment receipt in e2e tests

Introduce a 1-second delay after detecting successful payment receipt in
end-to-end tests to ensure downstream processes have sufficient time to
stabilize before proceeding.

Author: doitian

tests/bruno/e2e/cross-chain-hub/08-check-hub-received-wrapped-btc.bru

@@ -53,6 +53,7 @@ script:post-response {
 
   if (parseInt(res.body.result.channels[0].local_balance, 16) >= 100000) {
     console.log("Hub has received the payment");
+    await new Promise(r => setTimeout(r, 1000));
     bru.setVar("iteration", 0);
   } else if (i+1 < n) {
     await new Promise(r => setTimeout(r, 500));

tests/bruno/e2e/cross-chain-hub/14-check-hub-received-btc-in-lnd.bru

@@ -33,6 +33,7 @@ script:post-response {
 
   if (parseInt(res.body.local_balance.sat, 10) === 50000) {
     console.log("Hub has received the payment");
+    await new Promise(r => setTimeout(r, 1000));
     bru.setVar("iteration", 0);
   } else if (i+1 < n) {
     await new Promise(r => setTimeout(r, 500));