dpif: Fix infinite netlink loop in dpif_execute_helper_cb.

dpif: Fix infinite netlink loop in dpif_execute_helper_cb.

When a meter action is encountered and stored in the auxiliary
structure, and subsequently, a non-meter action is processed
within a nested list during callback execution, an infinite
loop is triggered.

This patch maintains the current behavior but stores all
required meter actions in an ofpbuf for deferred execution.

Reported-at: https://patchwork.ozlabs.org/project/openvswitch/patch/20250506022337.3242-1-danieldin186@gmail.com/
Fixes: 076caa2fb077 ("ofproto: Meter translation.")
Acked-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>