Stabilize pov-recovery zombienet (#2611)

Smoldot sometimes stops reporting finalized blocks to us. Since we are
recovering from the relay chain with a huge delay on full nodes, we can
not rely on import notifications to set the best block. Because
sometimes we also do not receive finality notifications, the height
check in zombienet fails.

Proper solution is to update smoldot, there have been some changes since
the version we use. But upgrade is blocked by version conflict which
will be resolved with
https://github.com/paritytech/polkadot-sdk/pull/1631.