Bump NLog.Extensions.Logging in /src/NLog.Web.AspNetCore (#567)

Bumps [NLog.Extensions.Logging](https://github.com/NLog/NLog.Extensions.Logging) from 1.6.3 to 1.6.4.
- [Release notes](https://github.com/NLog/NLog.Extensions.Logging/releases)
- [Changelog](https://github.com/NLog/NLog.Extensions.Logging/blob/master/CHANGELOG.MD)
- [Commits](NLog/NLog.Extensions.Logging@v1.6.3...v1.6.4)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

src/NLog.Web.AspNetCore/NLog.Web.AspNetCore.csproj

@@ -64,7 +64,7 @@ See also https://github.com/NLog/NLog.Web/releases
     <DefineConstants>$(DefineConstants);ASP_NET_CORE;ASP_NET_CORE3</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="NLog.Extensions.Logging" Version="1.6.3" />
+    <PackageReference Include="NLog.Extensions.Logging" Version="1.6.4" />
   </ItemGroup>
   <ItemGroup Condition=" '$(TargetFramework)' == 'net451' ">
     <Reference Include="System" />