Drop lingering <NotFound> content + cross-link Status Code Pages 8.0

[guardrex]

Description

There's probably lingering <NotFound> content to purge for >=8.0.

Add/replace with Status Code Pages, including adding it to the Fundamentals > Handle errors article, possibly also cross-linking from the Routing article.

Status Code Pages in the main doc set ...

https://learn.microsoft.com/en-us/aspnet/core/fundamentals/error-handling?view=aspnetcore-8.0#usestatuscodepages

xref:fundamentals/error-handling#usestatuscodepages

Also, make this a Release Notes article entry.

Page URL

https://learn.microsoft.com/en-us/aspnet/core/blazor/fundamentals/handle-errors?view=aspnetcore-8.0

Content source URL

https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/blazor/fundamentals/handle-errors.md

Document ID

66a0b1c2-c45c-98ca-9808-6f340a861c44

Article author

guardrex

[guardrex]

Checked all occurrences ... this is covered 👍.