Bump the core group across 1 directory with 2 updates

Bumps the core group with 2 updates in the /src/AzurePipelinesToGitHubActionsConverter.Core directory: [GitHubActionsDotNet](https://github.com/samsmithnz/GitHubActionsDotNet) and [YamlDotNet](https://github.com/aaubry/YamlDotNet).


Updates `GitHubActionsDotNet` from 1.3.19 to 1.3.20
- [Release notes](https://github.com/samsmithnz/GitHubActionsDotNet/releases)
- [Commits](samsmithnz/GitHubActionsDotNet@v1.3.19...v1.3.20)

Updates `YamlDotNet` from 15.1.2 to 15.1.4
- [Release notes](https://github.com/aaubry/YamlDotNet/releases)
- [Commits](aaubry/YamlDotNet@v15.1.2...v15.1.4)

---
updated-dependencies:
- dependency-name: GitHubActionsDotNet
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: core
- dependency-name: YamlDotNet
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: core
...

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

src/AzurePipelinesToGitHubActionsConverter.Core/AzurePipelinesToGitHubActionsConverter.Core.csproj

@@ -22,10 +22,10 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="GitHubActionsDotNet" Version="1.3.19" />
+    <PackageReference Include="GitHubActionsDotNet" Version="1.3.20" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" />
     <PackageReference Include="System.Text.Json" Version="8.0.3" />
-    <PackageReference Include="YamlDotNet" Version="15.1.2" />
+    <PackageReference Include="YamlDotNet" Version="15.1.4" />
   </ItemGroup>
 
 </Project>