Work around flake in the Couchbase 3 integration tests (#7357)

## Summary of changes

Work around flake in the Couchbase 3 integration tests

## Reason for change

In #7029 we added code to workaround infra flake in the couchbase tests
by looking for `AuthenticationException`. However, in Couchbase 3,
`AuthenticationFailureException` is thrown instead, so we should look
for that too.

Additionally, I noticed that if I just run the sample locally, with no
couchbase running, a totally different issue arises. Working abound that
by trying to explicitly connect, and timing out if that fails

## Implementation details

Add `AuthenticationFailureException` and `UnambiguousTimeoutException`
to the ignored list. Re-throwing (instead of swallowing) when an error
occurs during auth (as we can't continue)

## Test coverage

Tested locally, and confirmed we return the skip code.

Author: andrewlock

tracer/test/test-applications/integrations/Samples.Couchbase3/Program.cs

@@ -5,16 +5,18 @@
 using System.Threading.Tasks;
 using Couchbase;
 using Couchbase.Core;
+using Couchbase.Core.Exceptions;
 
 namespace Samples.Couchbase3
 {
     internal class Program
     {
-        private static bool ContainsAuthenticationException(Exception ex) => ex switch
+        private static bool ContainsIgnorableException(Exception ex) => ex switch
         {
-            AuthenticationException => true,
-            AggregateException aggEx => aggEx.InnerExceptions.Any(ContainsAuthenticationException),
-            { InnerException: { } inner } => ContainsAuthenticationException(inner),
+            AuthenticationException or AuthenticationFailureException => true,
+            UnambiguousTimeoutException => true,
+            AggregateException aggEx => aggEx.InnerExceptions.Any(ContainsIgnorableException),
+            { InnerException: { } inner } => ContainsIgnorableException(inner),
             _ => false,
         };
 
@@ -31,16 +33,13 @@ private static async Task<int> Main()
             try
             {
                 cluster = await Cluster.ConnectAsync(options);
+                await cluster.WaitUntilReadyAsync(TimeSpan.FromSeconds(15));
             }
-            catch (Exception ex)
+            catch (Exception ex) when (ContainsIgnorableException(ex))
             {
                 Console.WriteLine("Exception during execution " + ex);
-
-                if (ContainsAuthenticationException(ex))
-                {
-                    Console.WriteLine("Exiting with skip code (13)");
-                    return 13;
-                }
+                Console.WriteLine("Exiting with skip code (13)");
+                return 13;
             }
 
             // get a bucket reference