Revert "Bump xunit.runner.visualstudio from 2.4.5 to 2.5.0 (#367)" (#387)

This reverts commit 67d717b.

Author: bitfaster

BitFaster.Caching.UnitTests/BitFaster.Caching.UnitTests.csproj

@@ -14,7 +14,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.1" />
     <PackageReference Include="Moq" Version="4.20.69" />
     <PackageReference Include="xunit" Version="2.5.0" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.0">
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>