Bump UmbracoCms from 8.6.1 to 8.10.0 in /TestSite

Bumps [UmbracoCms](https://github.com/umbraco/umbraco-cms) from 8.6.1 to 8.10.0.
- [Release notes](https://github.com/umbraco/umbraco-cms/releases)
- [Commits](umbraco/Umbraco-CMS@release-8.6.1...release-8.10.0)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

TestSite/packages.config

@@ -61,7 +61,7 @@
   <package id="System.Threading.Tasks.Dataflow" version="4.11.0" targetFramework="net472" />
   <package id="System.ValueTuple" version="4.5.0" targetFramework="net472" />
   <package id="Umbraco.SqlServerCE" version="4.0.0.1" targetFramework="net472" />
-  <package id="UmbracoCms" version="8.6.1" targetFramework="net472" />
+  <package id="UmbracoCms" version="8.10.0" targetFramework="net472" />
   <package id="UmbracoCms.Core" version="8.6.1" targetFramework="net472" />
   <package id="UmbracoCms.Web" version="8.6.1" targetFramework="net472" />
   <package id="UmbracoForms" version="8.7.0" targetFramework="net472" />