devmode-test: stop requiring python2 work

We don't need python2 anymore, so let it go.

BUG=chromium:1197478
TEST=`./devinstall_test.py betty ../../../build/images/betty/latest/chromiumos_test_image.bin` works

Change-Id: I09dd8de25bb5fe84df04f94de3b0ede3e38390f8
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crostestutils/+/2821652
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Reviewed-by: Dhanya Ganesh <dhanyaganesh@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
(cherry picked from commit 37b6600bbe6aa4509d0ab2ce9d21b303a22f287f)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crostestutils/+/2885284
Tested-by: George Engelbrecht <engeg@google.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: George Engelbrecht <engeg@google.com>
diff --git a/devmode-test/devinstall_test.py b/devmode-test/devinstall_test.py
index 45f28e4..32516dc 100755
--- a/devmode-test/devinstall_test.py
+++ b/devmode-test/devinstall_test.py
@@ -147,7 +147,7 @@
       # Symlinks can be tricky, and running python from one place might work
       # while it fails from another.  Test all the prefixes (and $PATH).
       for prefix in ('/usr/bin', '/usr/local/bin', '/usr/local/usr/bin', ''):
-        for prog in ('python', 'python2', 'python3'):
+        for prog in ('python', 'python3'):
           self.device.run(['sudo', '-u', 'chronos', '--',
                            os.path.join(prefix, prog),
                            '-c', '"print(\'hello world\')"'])