fix: Manually link_fields from flags before rename_doc
diff --git a/erpnext/patches/v13_0/healthcare_lab_module_rename_doctypes.py b/erpnext/patches/v13_0/healthcare_lab_module_rename_doctypes.py
index 9af0a8d..2549a1e 100644
--- a/erpnext/patches/v13_0/healthcare_lab_module_rename_doctypes.py
+++ b/erpnext/patches/v13_0/healthcare_lab_module_rename_doctypes.py
@@ -2,6 +2,7 @@
 import frappe
 from frappe.model.utils.rename_field import rename_field
 
+
 def execute():
 	if frappe.db.exists('DocType', 'Lab Test') and frappe.db.exists('DocType', 'Lab Test Template'):
 		# rename child doctypes
@@ -17,7 +18,12 @@
 		frappe.reload_doc('healthcare', 'doctype', 'lab_test_template')
 
 		for old_dt, new_dt in doctypes.items():
-			if not frappe.db.table_exists(new_dt) and frappe.db.table_exists(old_dt):
+			frappe.flags.link_fields = {}
+			should_rename = (
+				frappe.db.table_exists(old_dt)
+				and not frappe.db.table_exists(new_dt)
+			)
+			if should_rename:
 				frappe.reload_doc('healthcare', 'doctype', frappe.scrub(old_dt))
 				frappe.rename_doc('DocType', old_dt, new_dt, force=True)
 				frappe.reload_doc('healthcare', 'doctype', frappe.scrub(new_dt))