self-hosted runners: mark associated network resources for deletion

The network interface and the public IP do not need to exist without the
VM. Therefore, let's let them be deleted when the VM is deleted.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

azure-self-hosted-runners/azure-arm-template-example-parameters.json

@@ -47,7 +47,7 @@
             "value": "Standard"
         },
         "pipDeleteOption": {
-            "value": "Detach"
+            "value": "Delete"
         },
         "osDiskType": {
             "value": "Premium_LRS"
@@ -56,7 +56,7 @@
             "value": "Delete"
         },
         "nicDeleteOption": {
-            "value": "Detach"
+            "value": "Delete"
         },
         "patchMode": {
             "value": "AutomaticByOS"