Add fixups for Node 20

Author: Shaptic

.github/workflows/tests.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       max-parallel: 4
       matrix:
-        node-version: [16, 18, 20]
+        node-version: [18, 20]
 
     steps:
       - name: Checkout

test/unit/server/simulate_transaction_test.js

@@ -153,8 +153,6 @@ describe('Server#simulateTransaction', async function (done) {
   });
 
   xit('simulates fee bump transactions');
-
-  done();
 });
 
 function cloneSimulation(sim) {
@@ -195,10 +193,10 @@ async function buildAuthEntry(address) {
 
   // do some voodoo to make this return a deterministic auth entry
   const kp = Keypair.fromSecret(randomSecret);
-  let entry = authorizeInvocation(kp, 1, root);
-  entry.credentials().address().nonce(new xdr.Int64(0xdeadbeef));
-
-  return authorizeEntry(entry, kp, 1); // overwrites signature w/ above nonce
+  return authorizeInvocation(kp, 1, root).then(entry => {
+    entry.credentials().address().nonce(new xdr.Int64(0xdeadbeef));
+    return authorizeEntry(entry, kp, 1); // overwrites signature w/ above nonce
+  });
 }
 
 async function invokeSimulationResponse(address) {