Context
Dependabot PR #3235 attempted to upgrade Microsoft.OpenApi from 2.7.5 to 3.9.0. Testing it in the consolidated dependency branch showed that Microsoft.AspNetCore.OpenApi 10.0.10 and the .NET 10 OpenAPI source generator still target Microsoft.OpenApi 2.x. The 3.9.0 graph produces assembly conflicts and compile failures in generated OpenAPI code.
Microsoft documents Microsoft.OpenApi 3.x adoption as an ASP.NET Core 11 change, so the consolidated PR must retain 2.7.5 while the repository targets .NET 10.
Reference: https://learn.microsoft.com/aspnet/core/breaking-changes/11/microsoft-openapi-3x
Acceptance criteria
- Upgrade the repository to the compatible .NET and Microsoft.AspNetCore.OpenApi release line.
- Upgrade Microsoft.OpenApi to 3.x.
- Migrate JsonElementOneOfNullCleanup and any other OpenAPI customization code to the 3.x object model.
- Regenerate and review the checked-in OpenAPI contract and portal schema.
- Run eng/ci/ci-local.sh --all --full and the OpenAPI drift check.
Context
Dependabot PR #3235 attempted to upgrade Microsoft.OpenApi from 2.7.5 to 3.9.0. Testing it in the consolidated dependency branch showed that Microsoft.AspNetCore.OpenApi 10.0.10 and the .NET 10 OpenAPI source generator still target Microsoft.OpenApi 2.x. The 3.9.0 graph produces assembly conflicts and compile failures in generated OpenAPI code.
Microsoft documents Microsoft.OpenApi 3.x adoption as an ASP.NET Core 11 change, so the consolidated PR must retain 2.7.5 while the repository targets .NET 10.
Reference: https://learn.microsoft.com/aspnet/core/breaking-changes/11/microsoft-openapi-3x
Acceptance criteria