chore(deps): update xunit-dotnet monorepo to v2.7.0

| datasource | package              | from  | to    |
| ---------- | -------------------- | ----- | ----- |
| nuget      | xunit                | 2.6.6 | 2.7.0 |
| nuget      | xunit.runner.console | 2.6.6 | 2.7.0 |

Author: renovate[bot]

OpenXmlPowerTools.Tests/OpenXmlPowerTools.Tests.csproj

@@ -7,12 +7,12 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
-    <PackageReference Include="xunit" Version="2.6.6" />
+    <PackageReference Include="xunit" Version="2.7.0" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.7">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="xunit.runner.console" Version="2.6.6">
+    <PackageReference Include="xunit.runner.console" Version="2.7.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>