docs: remove entry for fix within release

This commit removes an entry that was fixed in the same release as it
was introduced. So nobody should've been running into it yet.

docs/release-notes/release-notes-0.18.0.md

@@ -124,9 +124,6 @@
   for the internal channel funding flow (Single and Batch Funding Flow). Now
   UTXOs which are unconfirmed and originated from the sweeper subsystem are not
   selected because they bear the risk of being replaced (BIP 125 RBF).
-
-* [Fixed](https://github.com/lightningnetwork/lnd/pull/8685) `lncli bumpfee`
-  parsing of the immediate/force flag.
   
 * [Fixed](https://github.com/lightningnetwork/lnd/pull/8621) the behaviour of
   neutrino LND nodes which would lose sync in case they had very unstable