Bump YamlDotNet and Microsoft.NETFramework.ReferenceAssemblies (#804)

Bumps [YamlDotNet](https://github.com/aaubry/YamlDotNet) and [Microsoft.NETFramework.ReferenceAssemblies](https://github.com/Microsoft/dotnet). These dependencies needed to be updated together.

Updates `YamlDotNet` from 16.2.0 to 16.2.1
- [Release notes](https://github.com/aaubry/YamlDotNet/releases)
- [Commits](aaubry/YamlDotNet@v16.2.0...v16.2.1)

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

---
updated-dependencies:
- dependency-name: YamlDotNet
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: Microsoft.NETFramework.ReferenceAssemblies
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

NGitLab.Mock/NGitLab.Mock.csproj

@@ -12,7 +12,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="YamlDotNet" Version="16.2.0" />
+    <PackageReference Include="YamlDotNet" Version="16.2.1" />
   </ItemGroup>
 
   <ItemGroup Condition="$(TargetFramework) == 'net472'">