Add support for Kiota generation updates

Author: Andrew Omondi (from Dev Box)

.azure-pipelines/generation-templates/build-and-publish-kiota.yml

@@ -1,5 +1,7 @@
 steps:
 - template: use-dotnet-sdk.yml
+  parameters:
+    version: '8.x' # Kiota is a NET8 app
 
 - checkout: kiota
   displayName: checkout kiota

.azure-pipelines/generation-templates/set-up-for-generation-kiota.yml

@@ -10,6 +10,8 @@ parameters:
 steps:
 - template: set-user-config.yml
 - template: use-dotnet-sdk.yml
+  parameters:
+    version: '8.x' # Kiota is a NET8 app
 - ${{ parameters.downloadSteps }}
 
 #Download the openAPI artifacts