This might fix the intermittent failures in the `unregister_all_during_call` test, as suggested by https://github.com/bitcoin/bitcoin/pull/28150#issuecomment-1650075726
A description of what is the likely problem can be found here: https://github.com/bitcoin/bitcoin/issues/28146#issuecomment-1649931679
The solution chosen by core#28150 does not work for our version of the validationinterface tests, as we need a `ChainstateManager` to be set up (see `D12022`)
Example of failure that happened today: https://reviews.bitcoinabc.org/D14387#322665