[Failing test]: Unexpected number of transactions in mempool in neutrino channel force closure itest

[Chinwendu20]

Creating this issue to track the failing channel force closure test using the neutrino backend on the CI as seen in these pull requests:

https://github.com/lightningnetwork/lnd/actions/runs/9089660152/job/25069074366?pr=8759#step:5:767

https://github.com/lightningnetwork/lnd/actions/runs/9270373663/job/25641223443?pr=8516#step:5:385