perf: use `get_cached_value` instead of `db.get_value` in controllers (#32776)

diff --git a/erpnext/controllers/taxes_and_totals.py b/erpnext/controllers/taxes_and_totals.py
index 81de682..c6a634b 100644
--- a/erpnext/controllers/taxes_and_totals.py
+++ b/erpnext/controllers/taxes_and_totals.py
@@ -1056,7 +1056,7 @@
 		company_currency = erpnext.get_company_currency(self.doc.company)
 		for d in self.doc.get(self.tax_field):
 			if not d.account_currency:
-				account_currency = frappe.db.get_value("Account", d.expense_account, "account_currency")
+				account_currency = frappe.get_cached_value("Account", d.expense_account, "account_currency")
 				d.account_currency = account_currency or company_currency
 
 	def set_exchange_rate(self):