Fix sign check

- most likely cause of failing official builds
- small typo in #10340: need to find .cab files _below_ `$(TargetDir)`

Author: dougbu

src/Installers/Windows/Wix.targets

@@ -49,7 +49,7 @@
           AfterTargets="Build">
     <Copy SourceFiles="$(TargetPath)" DestinationFolder="$(InstallersOutputPath)" />
     <ItemGroup>
-      <_cabs Include="$(TargetDir)\*.cab" />
+      <_cabs Include="$(TargetDir)**/*.cab" />
     </ItemGroup>
     <Copy SourceFiles="@(_cabs)" DestinationFolder="$(InstallersOutputPath)" />
   </Target>