Remove flex restriction for OTel support

OTel is now supported in all Azure Functions plans/skus.

Author: BigMorty

includes/functions-opentelemetry-preview-note.md

@@ -6,4 +6,4 @@ ms.date: 05/17/2024
 ms.author: glenga
 ---
 > [!IMPORTANT]  
-> OpenTelemetry support for Azure Functions is currently in preview, and your app must be hosted in a [Flex Consumption plan](../articles/azure-functions/flex-consumption-plan.md) to use OpenTelemetry. 
+> OpenTelemetry support for Azure Functions is currently in preview.