refactor: use maps.Copy for cleaner map handling

Signed-off-by: xinhangzhou <shuangcui@aliyun.com>

docs/release-notes/release-notes-0.19.0.md

@@ -433,6 +433,9 @@ The underlying functionality between those two options remain the same.
   inputs spending logic in the sweeper so it can properly handle missing inputs
   and recover from restart.
 
+* A code refactor to [use maps.Copy instead of manually copying map
+   elements](https://github.com/lightningnetwork/lnd/pull/9630).
+
 
 ## Tooling and Documentation