samples: chre: exclude qemu_leon3
samples: chre: exclude qemu_leon3

This test used to only run on native_posix due to the test filter until
e478a4e850 was merged. Now it's running on all platforms but it's failing
on qemu_leon3 for some address alignment issue.

Signed-off-by: Fabio Baltieri <1c55e39c05d9ab42261288cf330256b2af6ba179@google.com>

zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr