perf: Replace db.get_all with db.exists in is_holiday

- widely used function call, fetching all rows for holidays

erpnext/hr/doctype/employee/employee.json

@@ -813,7 +813,7 @@
  "idx": 24,
  "image_field": "image",
  "links": [],
- "modified": "2021-06-17 11:31:37.730760",
+ "modified": "2022-07-18 20:03:43.188705",
  "modified_by": "Administrator",
  "module": "HR",
  "name": "Employee",

erpnext/hr/doctype/holiday_list/holiday_list.py

@@ -115,6 +115,6 @@ def is_holiday(holiday_list, date=None):
 	if date is None:
 		date = today()
 	if holiday_list:
-		return bool(frappe.get_all("Holiday List", dict(name=holiday_list, holiday_date=date)))
+		return bool(frappe.db.exists("Holiday List", {"name": holiday_list, "holiday_date": date}))
 	else:
 		return False