refactor: change server_action args (#39756)

args are now flat, no need to accept them as dict

ref: https://github.com/frappe/frappe/pull/24782
diff --git a/erpnext/selling/doctype/customer/customer.py b/erpnext/selling/doctype/customer/customer.py
index 415216c..3744922 100644
--- a/erpnext/selling/doctype/customer/customer.py
+++ b/erpnext/selling/doctype/customer/customer.py
@@ -572,15 +572,14 @@
 
 
 @frappe.whitelist()
-def send_emails(args):
-	args = json.loads(args)
-	subject = _("Credit limit reached for customer {0}").format(args.get("customer"))
+def send_emails(customer, customer_outstanding, credit_limit, credit_controller_users_list):
+	if isinstance(credit_controller_users_list, str):
+		credit_controller_users_list = json.loads(credit_controller_users_list)
+	subject = _("Credit limit reached for customer {0}").format(customer)
 	message = _("Credit limit has been crossed for customer {0} ({1}/{2})").format(
-		args.get("customer"), args.get("customer_outstanding"), args.get("credit_limit")
+		customer, customer_outstanding, credit_limit
 	)
-	frappe.sendmail(
-		recipients=args.get("credit_controller_users_list"), subject=subject, message=message
-	)
+	frappe.sendmail(recipients=credit_controller_users_list, subject=subject, message=message)
 
 
 def get_customer_outstanding(