Revert "glib-2.0: add workaround to fix codegen.py.test failing"

This reverts commit afc9ba7d.

Ptest-runner was upgraded in e3fd8f17,
which means we no longer need to limit glib-2.0 ptest output.

[YOCTO #14170]

Signed-off-by: Yi Fan Yu <yifan.yu@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>