Fix cargo clippy warnings

Disabled warnings for nursery/tmp_plan as it's going to be replaced
anyways

crates/file_store/src/lib.rs

@@ -6,7 +6,7 @@ use bdk_chain::{
 };
 pub use file_store::*;
 
-impl<'de, K, P> PersistBackend<K, P> for KeychainStore<K, P>
+impl<K, P> PersistBackend<K, P> for KeychainStore<K, P>
 where
     K: Ord + Clone + core::fmt::Debug,
     P: ChainPosition,

crates/file_store/tests/test_file_store.rs

@@ -4,7 +4,6 @@ use bdk_chain::{
     TxHeight,
 };
 use bdk_file_store::{FileError, IterError, KeychainStore, MAGIC_BYTES, MAGIC_BYTES_LEN};
-use serde;
 use std::{
     io::{Read, Write},
     vec::Vec,