Make CreateConnection return explicit instead of using local variable

Co-authored-by: aaronpowell <434140+aaronpowell@users.noreply.github.com>

Author: Copilot

src/CommunityToolkit.Aspire.Microsoft.Data.Sqlite/AspireSqliteExtensions.cs

@@ -102,8 +102,7 @@ private static void RegisterSqliteServices(
         SqliteConnection CreateConnection(IServiceProvider sp, object? key)
         {
             ConnectionStringValidation.ValidateConnectionString(settings.ConnectionString, connectionName, DefaultConfigSectionName);
-            var connection = new SqliteConnection(settings.ConnectionString);
-            return connection;
+            return new SqliteConnection(settings.ConnectionString);
         }
     }
 }