samples/bluetooth: peripheral: Remove nucleo_f429zi from withelist

samples/bluetooth/peripheral couldn't build on nucleo_f429zi
since settings dependency on flash erase bock size.
On this series, flash erase are done per sector with sector
having varying size, so erase block size can't be used directly.
This has to be sorted, but for now nucleo_f429zi is removed from
sample withelist to unlock CI.


Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>