Fix race condition in EventFilterTestBase logger initialization (#673)

Increased timeout for logger initialization from 3 seconds to 10 seconds
to prevent intermittent test failures in CI environments under load.

The ForwardAllEventsTestEventListener sometimes takes longer than 3 seconds
to initialize and respond with an "OK" signal, causing random test failures
with timeout errors. This fix gives the logger more time to initialize while
also converting to async API for better async/await pattern consistency.

Fixes test failures in:
- ExceptionEventFilterTests.ShouldReportCorrectMessageCount
- CustomEventFilterErrorTests.Messages_can_be_muted_from_now_on

Author: Aaronontheweb

src/Akka.Hosting.TestKit.Tests/TestEventListenerTests/EventFilterTestBase.cs

@@ -49,7 +49,7 @@ protected override async Task BeforeTestStart()
             SendRawLogEventMessage(initLoggerMessage);
             try
             {
-                ExpectMsg("OK");
+                await ExpectMsgAsync("OK", TimeSpan.FromSeconds(10));
             }
             catch (Exception e)
             {