tests: reset root logger level in cmdline tests

tests/cli/test_cmdline.py

@@ -37,10 +37,15 @@ class CommandLineTestCase(unittest.TestCase):
              patch("streamlink_cli.output.player.sleep"):
             mock_argv.__getitem__.side_effect = lambda x: args[x]
             mock_popen.return_value = Mock(poll=Mock(side_effect=poll_factory([None, 0])))
+
+            level = streamlink_cli.main.logger.root.level
+
             try:
                 streamlink_cli.main.main()
             except SystemExit as exc:
                 actual_exit_code = exc.code
+            finally:
+                streamlink_cli.main.logger.root.level = level
 
         assert exit_code == actual_exit_code
         assert mock_setup_streamlink.call_count == 1