Bump NLog from 4.7.7 to 4.7.8

Bumps [NLog](https://github.com/NLog/NLog) from 4.7.7 to 4.7.8.
- [Release notes](https://github.com/NLog/NLog/releases)
- [Changelog](https://github.com/NLog/NLog/blob/dev/CHANGELOG.md)
- [Commits](https://github.com/NLog/NLog/commits)

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

src/NLog.Extensions.Logging/NLog.Extensions.Logging.csproj

@@ -75,7 +75,7 @@ Full changelog: https://github.com/NLog/NLog.Extensions.Logging/blob/master/CHAN
     <DefineConstants>$(DefineConstants);NETSTANDARD</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="NLog" Version="4.7.7" />
+    <PackageReference Include="NLog" Version="4.7.8" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
   </ItemGroup>
   <ItemGroup Condition=" '$(TargetFramework)' == 'net451' ">