selftests/nolibc: drop test chmod_net

The test relies on /proc/$PID/net to allow chmod() operations.
It is the only file or directory in /proc/$PID/ to allow this and a bug.
That bug will be fixed in the next patch in the series and therefore
the test would start failing.

Link: https://lore.kernel.org/lkml/d0d111ef-edae-4760-83fb-36db84278da1@t-8ch.de/


Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Fixes: b4844fa0 ("selftests/nolibc: implement a few tests for various syscalls")
Tested-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Message-Id: <20230624-proc-net-setattr-v1-1-73176812adee@weissschuh.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>