Bump Microsoft.NETFramework.ReferenceAssemblies and System.Threading.Tasks.Extensions

Bumps [Microsoft.NETFramework.ReferenceAssemblies](https://github.com/Microsoft/dotnet) and [System.Threading.Tasks.Extensions](https://github.com/dotnet/maintenance-packages). These dependencies needed to be updated together.

Updates `Microsoft.NETFramework.ReferenceAssemblies` from 1.0.3 to 1.0.3
- [Commits](https://github.com/Microsoft/dotnet/commits)

Updates `System.Threading.Tasks.Extensions` from 4.6.0 to 4.6.2
- [Release notes](https://github.com/dotnet/maintenance-packages/releases)
- [Commits](https://github.com/dotnet/maintenance-packages/commits)

---
updated-dependencies:
- dependency-name: Microsoft.NETFramework.ReferenceAssemblies
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: System.Threading.Tasks.Extensions
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

tests/NHapi.Base.NUnit/NHapi.Base.NUnit.csproj

@@ -44,7 +44,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
     <!-- can remove this with next version of nunit https://github.com/nunit/nunit/pull/4582 -->
-    <PackageReference Include="System.Threading.Tasks.Extensions" Version="4.6.0" />
+    <PackageReference Include="System.Threading.Tasks.Extensions" Version="4.6.2" />
   </ItemGroup>
 
 </Project>