Update Serilog dependency version

Author: bdovaz

src/Serilog.Enrichers.Thread/Serilog.Enrichers.Thread.csproj

@@ -20,7 +20,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Serilog" Version="2.3.0" />
+    <PackageReference Include="Serilog" Version="2.9.0" />
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net45' ">