tests/lib/mpsc_pbuf: Switch to native_sim

Enable this test which runs in native_posix in native_sim,
Switch from native_posix to native_sim as default test platform

Signed-off-by: Alberto Escolar Piedras <[email protected]>

Author: aescolar

tests/lib/mpsc_pbuf/testcase.yaml

@@ -16,8 +16,9 @@ tests:
       - qemu_x86_64
       - qemu_xtensa
       - native_posix
+      - native_sim
     integration_platforms:
-      - native_posix
+      - native_sim
 
   libraries.mpsc_pbuf.concurrent:
     tags: mpsc_pbuf