UBUNTU: [Debian] Use a python3 compatable kernel-testing repo

BugLink: https://bugs.launchpad.net/bugs/2004429

Switch to using a python3 compatible branch for the kernel-testing
scripts used for running autopkgtest. This in turn uses a python3
compatible fork of autotest.

Remove the autopkgtest dependency on python2, replacing it with python3.
Also remove the dependency on bzr as it's unused.

Signed-off-by: Francis Ginther <francis.ginther@canonical.com>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>

debian/tests/control

@@ -3,5 +3,5 @@ Depends: @builddeps@, fakeroot
 Restrictions: allow-stderr, skippable
 
 Tests: ubuntu-regression-suite
-Depends: build-essential, gcc-multilib [amd64 armhf i386], gdb, git, python2 | python, bzr
+Depends: build-essential, gcc-multilib [amd64 armhf i386], gdb, git, python3
 Restrictions: allow-stderr, isolation-machine, breaks-testbed, skippable

debian/tests/ubuntu-regression-suite

@@ -41,5 +41,6 @@ if [ "$sver" != "$rver" ]; then
     exit 1
 fi
 
-git clone --depth=1 git://git.launchpad.net/~canonical-kernel-team/+git/kernel-testing
+git clone --depth=1 -b autotest3 git://git.launchpad.net/~canonical-kernel-team/+git/kernel-testing
+git -C kernel-testing/ show HEAD -q
 kernel-testing/run-dep8-tests