Bump Microsoft.NETCore.UniversalWindowsPlatform in /SimpleSample.UWP

Bumps [Microsoft.NETCore.UniversalWindowsPlatform](https://github.com/dotnet/core-setup) from 6.0.5 to 6.0.6.
- [Release notes](https://github.com/dotnet/core-setup/releases)
- [Commits](https://github.com/dotnet/core-setup/commits)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

EntryCustomReturn.Forms.Plugin.UWP/EntryCustomReturn.Forms.Plugin.UWP.csproj

@@ -121,7 +121,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform">
-      <Version>6.1.9</Version>
+      <Version>6.0.6</Version>
     </PackageReference>
     <PackageReference Include="Xamarin.Forms">
       <Version>2.5.0.280555</Version>

SimpleSample.UWP/SimpleSample.UWP.csproj

@@ -128,7 +128,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform">
-      <Version>6.0.5</Version>
+      <Version>6.0.6</Version>
     </PackageReference>
     <PackageReference Include="Xamarin.Forms">
       <Version>2.5.0.122203</Version>