build(test): switch to AutoFixture.Xunit3 in test Directory.build.props

Author: perkops

README.md

@@ -22,10 +22,6 @@ Typical test project (excerpt):
     <PackageReference Include="xunit.v3" Version="3.0.1" />
     <PackageReference Include="Atc.Test" Version="$(LatestOrPinned)" />
   </ItemGroup>
-  <!-- Remove legacy AutoFixture.Xunit2 using if brought transitively -->
-  <ItemGroup>
-    <Using Remove="AutoFixture.Xunit2" />
-  </ItemGroup>
 </Project>
 ```
 

test/Directory.Build.props

@@ -16,7 +16,7 @@
 
   <ItemGroup>
     <Using Include="AutoFixture" />
-    <Using Include="AutoFixture.Xunit2" />
+    <Using Include="AutoFixture.Xunit3" />
     <Using Include="FluentAssertions" />
     <Using Include="NSubstitute" />
     <Using Include="Xunit" />