fix: frappe.whitelist for doc methods (#25231)

diff --git a/erpnext/payroll/doctype/payroll_entry/payroll_entry.py b/erpnext/payroll/doctype/payroll_entry/payroll_entry.py
index b520cda..1a6a534 100644
--- a/erpnext/payroll/doctype/payroll_entry/payroll_entry.py
+++ b/erpnext/payroll/doctype/payroll_entry/payroll_entry.py
@@ -183,6 +183,7 @@
 		""", (ss_status, self.start_date, self.end_date, self.name, self.salary_slip_based_on_timesheet), as_dict=as_dict)
 		return ss_list
 
+	@frappe.whitelist()
 	def submit_salary_slips(self):
 		self.check_permission('write')
 		ss_list = self.get_sal_slip_list(ss_status=0)
@@ -405,6 +406,7 @@
 		self.update(get_start_end_dates(self.payroll_frequency,
 			self.start_date or self.posting_date, self.company))
 
+	@frappe.whitelist()
 	def validate_employee_attendance(self):
 		employees_to_mark_attendance = []
 		days_in_payroll, days_holiday, days_attendance_marked = 0, 0, 0