WN update prev 5: Validaton Min API and OpenAPI (#35587)

* WN update prev 5: Validaton Min API and OpenAPI

* Removed unused empty file

* typo fix

* Update aspnetcore/release-notes/aspnetcore-10/includes/OpenApiPopulateXMLDocComments.md

Co-authored-by: Mike Kistler <[email protected]>

* Update aspnetcore/release-notes/aspnetcore-10/includes/OpenApiNetUpdatePrev.md

Co-authored-by: Tom Dykstra <[email protected]>

---------

Co-authored-by: Mike Kistler <[email protected]>
Co-authored-by: Tom Dykstra <[email protected]>

Author: 3 people

aspnetcore/release-notes/aspnetcore-10.0.md

@@ -61,7 +61,7 @@ This section describes new features for OpenAPI.
 
 [!INCLUDE[](~/release-notes/aspnetcore-10/includes/OpenApiSchemasInTransformers.md)]
 
-[!INCLUDE[](~/release-notes/aspnetcore-10/includes/OpenApiNetUpdatePrev17.md)]
+[!INCLUDE[](~/release-notes/aspnetcore-10/includes/OpenApiNetUpdatePrev.md)]
 
 ### Authentication and authorization
 

aspnetcore/release-notes/aspnetcore-10/includes/OpenApiNetUpdatePrev.md

@@ -0,0 +1,8 @@
+### OpenAPI.NET updated to Preview.18
+
+The OpenAPI.NET library used in ASP.NET Core OpenAPI document generation was upgraded to [v2.0.0-preview18](https://www.nuget.org/packages/Microsoft.OpenApi/2.0.0-preview.18). The v2.0.0-preview18 version improves compatibility with the updated library version.
+
+The previous v2.0.0-preview17 version included a number of bug fixes and improvements and also introduced some breaking changes. The breaking changes should only affect users that use document, operation, or schema transformers. Breaking changes in this version that may affect developers include the following:
+
+* [Ephemeral object properties are now in Metadata](https://github.com/microsoft/OpenAPI.NET/blob/main/docs/upgrade-guide-2.md#ephemeral-object-properties-are-now-in-metadata)
+* [Use HTTP Method Object Instead of Enum](https://github.com/microsoft/OpenAPI.NET/blob/main/docs/upgrade-guide-2.md#use-http-method-object-instead-of-enum)

aspnetcore/release-notes/aspnetcore-10/includes/OpenApiNetUpdatePrev17.md

@@ -31,3 +31,6 @@ app.MapPost("/products",
         => TypedResults.Ok(productId))
     .DisableValidation();
 ```
+
+> [!NOTE]
+> Several small improvements and fixes have been made to the Minimal APIs validation generator introduced in ASP.NET Core for .NET 10. To support future enhancements, the underlying validation resolver APIs are now marked as experimental. The top-level `AddValidation` APIs and the built-in validation filter remain stable and non-experimental.