Update payloads_spec.rb

Author: xHector1337

spec/modules/payloads_spec.rb

@@ -5200,6 +5200,15 @@
                           reference_name: 'windows/aarch64/exec'
   end
 
+  context 'windows/x64/download_exec' do
+    it_should_behave_like 'payload cached size is consistent',
+                          ancestor_reference_names: [
+                              'singles/windows/x64/download_exec'
+                          ],
+                          dynamic_size: false,
+                          modules_pathname: modules_pathname,
+                          reference_name: 'windows/x64/download_exec'
+  end
 
   context 'windows/x64/custom/bind_ipv6_tcp' do
     it_should_behave_like 'payload is not cached',