Bump YamlDotNet from 13.3.1 to 13.4.0

Bumps [YamlDotNet](https://github.com/aaubry/YamlDotNet) from 13.3.1 to 13.4.0.
- [Release notes](https://github.com/aaubry/YamlDotNet/releases)
- [Commits](aaubry/YamlDotNet@v13.3.1...v13.4.0)

---
updated-dependencies:
- dependency-name: YamlDotNet
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

NGitLab.Mock/NGitLab.Mock.csproj

@@ -13,7 +13,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="YamlDotNet" Version="13.3.1" />
+    <PackageReference Include="YamlDotNet" Version="13.4.0" />
   </ItemGroup>
 
   <ItemGroup Condition="$(TargetFramework) == 'net472'">