feat(wallet): cache txs when constructing full-scan/sync requests

crates/bdk/src/wallet/mod.rs

@@ -2419,6 +2419,7 @@ impl Wallet {
     /// start a blockchain sync with a spk based blockchain client.
     pub fn start_sync_with_revealed_spks(&self) -> SyncRequest {
         SyncRequest::from_chain_tip(self.chain.tip())
+            .cache_graph_txs(self.tx_graph())
             .populate_with_revealed_spks(&self.indexed_graph.index, ..)
     }
 
@@ -2432,6 +2433,7 @@ impl Wallet {
     /// in which the list of used scripts is not known.
     pub fn start_full_scan(&self) -> FullScanRequest<KeychainKind> {
         FullScanRequest::from_keychain_txout_index(self.chain.tip(), &self.indexed_graph.index)
+            .cache_graph_txs(self.tx_graph())
     }
 }