ASP.NET Built-in Metrics: Delete and forward to new location

[wadepickett]

Summary

• The ASP.NET Build-In Metrics topic has been removed in and, the TOC updated to point to its new location in the aspnetcore.docs repository. (The file was moved to there in a previous PR).
• Redirection was added to point to the new location of the ASP.NET Core Metrics topic.

Fixes #45580
Fixes dotnet/AspNetCore.Docs#35109

Internal preview test: ASP.NET Core metrics link in TOC
Select in the TOC: Built-in metrics > ASP.NET Core metrics

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Internal previews

📄 File	🔗 Preview link
docs/breadcrumb/toc.yml	docs/breadcrumb/toc
docs/core/diagnostics/built-in-metrics.md	docs/core/diagnostics/built-in-metrics
docs/navigate/tools-diagnostics/toc.yml	docs/navigate/tools-diagnostics/toc

[wadepickett]

Closing and reopening to attempt re-build since the OPS status checker seems to be having an existential crisis, absorbed in an endless loop of self-reflection...

[gewarren]

I left a suggestion with how a contextual TOC link works (you can also read about them in the contributor guide).

[wadepickett]

OH! You wanted a breadcrumb! Sorry, I was not catching on. Thanks!

[wadepickett]

Internal preview test: ASP.NET Core metrics link in TOC
Select in the TOC: Built-in metrics > ASP.NET Core metrics

[wadepickett]

@IEvangelist, this seems to work fine, but I'm not confident my entry in the docs/breadcrumb/toc.yml is in the right place. gewarren may not be available and I saw you had some contextual links in here so I'm picking on you. :)

Handy Internal preview test link: ASP.NET Core metrics link in TOC
Select in the TOC: Built-in metrics > ASP.NET Core metrics