fix flaky test: local_node_non_settling_solver

[MartinquaXD]

Description

This test appears to be flaky due to a bug in the new auction notficiation logic. It was introduced to avoid busy looping. Now we only start new auctions when we see a new block or a new order. However, so far we first updated the caches and then waited for the notification. This doesn't make a lot of sense since the notification indicates that the cache needs to be updated.
This resulted in test runs where we:

1. update the cache
2. see new order
3. start auction
4. skip empty auction because cache didn't include the order of step 2

Changes

Updated the autopilot to only update the cache after receiving the signal to start a new auction

How to test

Run flaky test runner on local_node_non_settling_solver (run)