Revert "Temporarily untag test_unbuffered_output"

This reverts commit aaed6ed.

Author: msimacek

graalpython/com.oracle.graal.python.test/src/tests/unittest_tags/test_cmd_line.txt

@@ -18,6 +18,7 @@
 *graalpython.lib-python.3.test.test_cmd_line.CmdLineTest.test_site_flag
 *graalpython.lib-python.3.test.test_cmd_line.CmdLineTest.test_stdin_readline
 *graalpython.lib-python.3.test.test_cmd_line.CmdLineTest.test_unbuffered_input
+*graalpython.lib-python.3.test.test_cmd_line.CmdLineTest.test_unbuffered_output
 *graalpython.lib-python.3.test.test_cmd_line.CmdLineTest.test_unmached_quote
 *graalpython.lib-python.3.test.test_cmd_line.CmdLineTest.test_usage
 *graalpython.lib-python.3.test.test_cmd_line.CmdLineTest.test_verbose