Removed metrics documentation for .NET (#11880)

Author: jamescrosswell

docs/platforms/dotnet/common/metrics/index.mdx

@@ -14,7 +14,6 @@ To set up and start sending metrics, click a link for one of the supported SDKs
 
 Metrics are currently available on the following platforms:
 
-- [.NET](/platforms/dotnet/metrics/)
 - [Android](/platforms/android/metrics/)
 - [Apple](/platforms/apple/metrics/)
 - [Astro](/platforms/javascript/guides/astro/metrics/)