XML comments not working

### Describe the bug I've tried to enable XML Comment support but they are not showing up in the OpenAPI document. ### Steps To reproduce ``` dotnet new webapi -controllers dotnet add package MartinCostello.OpenApi.Extensions ``` Enable them: ``` builder.Services.AddOpenApiExtensions((options) => { // Configure XML comments for the schemas in the OpenAPI document // from the assembly that the Program class is defined in. options.AddXmlComments<Program>(); // Add a custom transformation for the descriptions in the OpenAPI document options.DescriptionTransformations.Add((p) => p.ToUpper()); }); ``` Add `<GenerateDocumentationFile>true</GenerateDocumentationFile>` to the csproj. Add an XML comment to the controller: ```csharp /// <summary> /// This is a test /// </summary> /// <returns>Another test</returns> [HttpGet(Name = "GetWeatherForecast")] public IEnumerable<WeatherForecast> Get() { return Enumerable.Range(1, 5).Select(index => new WeatherForecast { Date = DateOnly.FromDateTime(DateTime.Now.AddDays(index)), TemperatureC = Random.Shared.Next(-20, 55), Summary = Summaries[Random.Shared.Next(Summaries.Length)] }) .ToArray(); } ``` These do not show up in the OpenAPI document. ### Expected behaviour I expect the contents of the XML comments to show up in the OpenAPI document. ### Actual behaviour They do not show up. ### Screenshots ### System information Windows 11 ``` .NET SDK: Version: 9.0.101 Commit: eedb237549 Workload version: 9.0.100-manifests.3068a692 MSBuild version: 17.12.12+1cce77968 Runtime Environment: OS Name: Windows OS Version: 10.0.22631 OS Platform: Windows RID: win-x64 Base Path: C:\Program Files\dotnet\sdk\9.0.101\ .NET workloads installed: [android] Installation Source: VS 17.11.35222.181 Manifest Version: 35.0.0-rc.2.152/9.0.100-rc.2 Manifest Path: C:\Program Files\dotnet\sdk-manifests\9.0.100-rc.2\microsoft.net.sdk.android\35.0.0-rc.2.152\WorkloadManifest.json Install Type: Msi [ios] Installation Source: VS 17.11.35222.181 Manifest Version: 18.0.9600-net9-rc2/9.0.100-rc.2 Manifest Path: C:\Program Files\dotnet\sdk-manifests\9.0.100-rc.2\microsoft.net.sdk.ios\18.0.9600-net9-rc2\WorkloadManifest.json Install Type: Msi [maui-windows] Installation Source: VS 17.11.35222.181 Manifest Version: 9.0.0-rc.2.24503.2/9.0.100-rc.2 Manifest Path: C:\Program Files\dotnet\sdk-manifests\9.0.100-rc.2\microsoft.net.sdk.maui\9.0.0-rc.2.24503.2\WorkloadManifest.json Install Type: Msi [maccatalyst] Installation Source: VS 17.11.35222.181 Manifest Version: 18.0.9600-net9-rc2/9.0.100-rc.2 Manifest Path: C:\Program Files\dotnet\sdk-manifests\9.0.100-rc.2\microsoft.net.sdk.maccatalyst\18.0.9600-net9-rc2\WorkloadManifest.json Install Type: Msi Configured to use loose manifests when installing new manifests. Host: Version: 9.0.0 Architecture: x64 Commit: 9d5a6a9aa4 .NET SDKs installed: 2.2.207 [C:\Program Files\dotnet\sdk] 3.1.426 [C:\Program Files\dotnet\sdk] 6.0.428 [C:\Program Files\dotnet\sdk] 7.0.407 [C:\Program Files\dotnet\sdk] 8.0.307 [C:\Program Files\dotnet\sdk] 8.0.400 [C:\Program Files\dotnet\sdk] 9.0.101 [C:\Program Files\dotnet\sdk] .NET runtimes installed: Microsoft.AspNetCore.All 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.App 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 6.0.33 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 7.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 8.0.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.NETCore.App 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 6.0.33 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 7.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 8.0.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 9.0.0-rc.2.24473.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.WindowsDesktop.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 6.0.33 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 7.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 8.0.8 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Microsoft.WindowsDesktop.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] Other architectures found: x86 [C:\Program Files (x86)\dotnet] registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation] Environment variables: Not set global.json file: Not found Learn more: https://aka.ms/dotnet/info Download .NET: https://aka.ms/dotnet/download ``` ### Additional context <!-- Add any other context about the problem here. -->