noise: repeat concurrent SSH verdict waiters test

Nothing signals that both waiters parked before FinishAuth, so one
pass mostly checks them one after the other.

hscontrol/noise_test.go

@@ -953,14 +953,20 @@ func TestSSHActionFollowUp_ConsumedVerdictNotReplayed(t *testing.T) {
 
 // TestSSHActionFollowUp_ConcurrentWaiters parks two follow-ups on one
 // session: exactly one may consume the verdict, the other re-decides.
+// FinishAuth can land before either waiter parks and nothing signals the
+// park, so the body repeats to exercise the both-parked order.
 func TestSSHActionFollowUp_ConcurrentWaiters(t *testing.T) {
 	t.Parallel()
 
+	const iterations = 200
+
 	for _, tc := range sshVerdictCases {
 		t.Run(tc.name, func(t *testing.T) {
 			t.Parallel()
 
 			f := newSSHVerdictFixture(t)
+
+			for range iterations {
 				authID, auth := f.mint(t)
 
 				var (
@@ -992,8 +998,9 @@ func TestSSHActionFollowUp_ConcurrentWaiters(t *testing.T) {
 					held++
 				}
 
-			assert.Equal(t, 1, carried, "exactly one waiter must carry the verdict")
+				require.Equal(t, 1, carried, "exactly one waiter must carry the verdict")
-			assert.Equal(t, 1, held, "the other waiter must re-delegate")
+				require.Equal(t, 1, held, "the other waiter must re-delegate")
+			}
 		})
 	}
 }