Allow stderr in the autopkgtest.

debian/changelog

@@ -1,3 +1,9 @@
+livecd-rootfs (23.10.28) UNRELEASED; urgency=medium
+
+  * Allow stderr in the autopkgtest.
+
+ -- Steve Langasek <steve.langasek@ubuntu.com>  Wed, 30 Aug 2023 08:27:27 -0700
+
 livecd-rootfs (23.10.27) mantic; urgency=medium
 
   * Add ubuntu to the list of targets we autopkgtest for on amd64, to ensure

debian/tests/control

@@ -1,6 +1,6 @@
 Tests: default-bootstraps
 Depends: @, lsb-release
-Restrictions: needs-root isolation-machine
+Restrictions: needs-root isolation-machine allow-stderr
 
 Tests: minimized
 Depends: @, lsb-release