Release QA issue template

- Add section for testing the [default migration workflow](https://fleetdm.com/docs/using-fleet/mdm-migration-guide#default-workflow) for macOS hosts.

Discussed w/ @georgekarrv that we may have caught the following bug if we were testing the migration workflow each release: #19512

We also thought it was a good idea to make this part of release QA in case the flow breaks w/ a never version of macOS.

.github/ISSUE_TEMPLATE/release-qa.md

@@ -99,6 +99,12 @@ Smoke tests are limited to core functionality and serve as a pre-release final r
 3. Verify able to run MDM commands on both macOS and Windows hosts from the CLI.
 </td><td>pass/fail</td></tr>
 
+<tr><td>MDM migration flow</td><td>Verify MDM enrollments, run MDM commands</td><td>
+
+1. Turn off MDM on an ADE-eligible macOS host and verify that the native, "Device Enrollment" macOS notification appears.
+2. Follow the "Turn on MDM" instructions and verify that MDM is turned on.
+</td><td>pass/fail</td></tr>
+
 <tr><td>Scripts</td><td>Verify script library and execution</td><td>
 
 1. Verify able to run a script on all host types from CLI.