Update dependency xunit.v3.extensibility.core to v4 (#496)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

src/Serilog.Sinks.XUnit.Injectable/Serilog.Sinks.XUnit.Injectable.csproj

@@ -44,6 +44,6 @@
         <PackageReference Include="Soenneker.Extensions.ValueTask" Version="4.0.118" />
         <PackageReference Include="Soenneker.Atomics.ValueBools" Version="4.0.35" />
         <PackageReference Include="Soenneker.Utils.ReusableStringWriter" Version="4.0.24" />
-        <PackageReference Include="xunit.v3.extensibility.core" Version="3.2.2" />
+        <PackageReference Include="xunit.v3.extensibility.core" Version="4.0.0" />
     </ItemGroup>
 </Project>