Remove CS0618 warning suppression for ExceptionHandlingMiddleware

Removed #pragma directives that suppressed CS0618 (obsolete API usage) warnings around app.UseMiddleware<ExceptionHandlingMiddleware>(). Obsolete warnings for this middleware will now be shown during compilation.

src/ReC.API/Program.cs

@@ -70,9 +70,7 @@ try
 
     var app = builder.Build();
 
-#pragma warning disable CS0618
     app.UseMiddleware<ExceptionHandlingMiddleware>();
-#pragma warning restore CS0618
 
     // Configure the HTTP request pipeline.
     if (app.Environment.IsDevelopment() || config.GetValue<bool>("UseSwagger"))