fix: use `get_all` instead of `get_list` while fetching SLA doctypes (#29216)

Co-authored-by: Ankush Menat <ankush@frappe.io>
diff --git a/erpnext/support/doctype/service_level_agreement/service_level_agreement.py b/erpnext/support/doctype/service_level_agreement/service_level_agreement.py
index b3348f1..ea617fd 100644
--- a/erpnext/support/doctype/service_level_agreement/service_level_agreement.py
+++ b/erpnext/support/doctype/service_level_agreement/service_level_agreement.py
@@ -853,7 +853,7 @@
 @frappe.whitelist()
 def get_sla_doctypes():
 	doctypes = []
-	data = frappe.get_list('Service Level Agreement',
+	data = frappe.get_all('Service Level Agreement',
 		{'enabled': 1},
 		['document_type'],
 		distinct=1