Update ApprovalTests to version 5.4.6

Author: 0xced

tests/Serilog.Formatting.Log4Net.Tests.csproj

@@ -8,7 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="ApprovalTests" Version="5.4.5" />
+    <PackageReference Include="ApprovalTests" Version="5.4.6" />
     <PackageReference Include="Codecov.MSBuild" Version="1.13.0" />
     <PackageReference Include="coverlet.msbuild" Version="3.0.3" PrivateAssets="all" />
     <PackageReference Include="FluentAssertions" Version="5.10.3" />