test: fix flaky carry forwarded leave expiry test (#30810)

diff --git a/erpnext/hr/doctype/leave_allocation/test_leave_allocation.py b/erpnext/hr/doctype/leave_allocation/test_leave_allocation.py
index dde52d7..a1d39d4 100644
--- a/erpnext/hr/doctype/leave_allocation/test_leave_allocation.py
+++ b/erpnext/hr/doctype/leave_allocation/test_leave_allocation.py
@@ -18,6 +18,7 @@
 	def setUp(self):
 		frappe.db.delete("Leave Period")
 		frappe.db.delete("Leave Allocation")
+		frappe.db.delete("Leave Ledger Entry")
 
 		emp_id = make_employee("test_emp_leave_allocation@salary.com", company="_Test Company")
 		self.employee = frappe.get_doc("Employee", emp_id)