Update the "What's new in ASP.NET Core 9.0" for .NET 9 Release Candidate 2

[danroth27]

Description

Update the "What's new in ASP.NET Core 9.0" for .NET 9 Release Candidate 2

Page URL

https://learn.microsoft.com/en-us/aspnet/core/release-notes/aspnetcore-9.0?view=aspnetcore-8.0

Content source URL

https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/release-notes/aspnetcore-9.0.md

Document ID

4e75ad25-2c3f-b28e-6a91-ac79a9c683b6

Article author

@Rick-Anderson

Related Issues

[guardrex]

Noting that for Blazor, client-side request streams is on #33693, which is scheduled for review in a couple of weeks.