Bump NLog from 4.7.5 to 4.7.6 (#458)

Bumps [NLog](https://github.com/NLog/NLog) from 4.7.5 to 4.7.6.
- [Release notes](https://github.com/NLog/NLog/releases)
- [Changelog](https://github.com/NLog/NLog/blob/v4.7.6/CHANGELOG.md)
- [Commits](NLog/NLog@v4.7.5...v4.7.6)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

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

@@ -66,7 +66,7 @@ Full changelog: https://github.com/NLog/NLog.Extensions.Logging/blob/master/CHAN
     <DefineConstants>$(DefineConstants);NETSTANDARD</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="NLog" Version="4.7.5" />
+    <PackageReference Include="NLog" Version="4.7.6" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
   </ItemGroup>
   <ItemGroup Condition=" '$(TargetFramework)' == 'net451' ">