fix: waitfor can be mising WriteTo section

Author: CumpsD

src/FunctionalLiving.Api/Infrastructure/WaitFor.cs

@@ -30,7 +30,7 @@ public static async Task SeqToBecomeAvailable(
                 .GetSection("Serilog:WriteTo")
                 .Get<WriteTo[]>();
 
-            var seq = writeTos.SingleOrDefault(to => "Seq".Equals(to.Name, StringComparison.InvariantCultureIgnoreCase));
+            var seq = writeTos?.SingleOrDefault(to => "Seq".Equals(to.Name, StringComparison.InvariantCultureIgnoreCase));
             if (seq == null)
                 return;