Update bug-report.yaml for 1.6-preview2 (#4675)

Author: duncanmacmichael

.github/ISSUE_TEMPLATE/bug-report.yaml

@@ -36,7 +36,7 @@ body:
       description: Specify the version of Windows App SDK (or Project Reunion) you're using.
       options:
         - "Windows App SDK 1.5.6: 1.5.240802000"
-        - "Windows App SDK 1.6 Preview 1: 1.6.240807006-preview1"
+        - "Windows App SDK 1.6 Preview 2: 1.6.240821007-preview2"
         - "Windows App SDK 1.6 Experimental 2: 1.6.240701003-experimental2"
   - type: dropdown
     attributes: