chore: Remove reference to Instructor doctype (#30903)

References:
https://github.com/frappe/erpnext/pull/30830
https://github.com/frappe/erpnext/commit/44c54f69f83e28fe205eb5f0e5dc4f161a8c0bba
diff --git a/erpnext/utilities/activation.py b/erpnext/utilities/activation.py
index cd7910c..7b2df5e 100644
--- a/erpnext/utilities/activation.py
+++ b/erpnext/utilities/activation.py
@@ -18,7 +18,6 @@
 		"Customer": 5,
 		"Delivery Note": 5,
 		"Employee": 3,
-		"Instructor": 5,
 		"Issue": 5,
 		"Item": 5,
 		"Journal Entry": 3,