reference .net 8 for key connector (#477)

Author: jlf0dev

docs/getting-started/business/key-connector.mdx

@@ -28,7 +28,7 @@ understand how it works.
 </Community>
 
 - [Web vault](../clients/web-vault) running locally
-- [.NET Core 5.0 SDK](https://www.microsoft.com/net/download/core)
+- [.NET 8.0 SDK](https://www.microsoft.com/net/download/core)
 
 ### macOS