test: correct naming series to avoid ValidationError (#25132)

diff --git a/erpnext/accounts/doctype/purchase_invoice/test_records.json b/erpnext/accounts/doctype/purchase_invoice/test_records.json
index e7166c5..9f9e90d 100644
--- a/erpnext/accounts/doctype/purchase_invoice/test_records.json
+++ b/erpnext/accounts/doctype/purchase_invoice/test_records.json
@@ -43,7 +43,7 @@
    }
   ],
   "grand_total": 0,
-  "naming_series": "_T-BILL",
+  "naming_series": "T-PINV-",
   "taxes": [
    {
     "account_head": "_Test Account Shipping Charges - _TC",
@@ -167,7 +167,7 @@
    }
   ],
   "grand_total": 0,
-  "naming_series": "_T-Purchase Invoice-",
+  "naming_series": "T-PINV-",
   "taxes": [
    {
     "account_head": "_Test Account Shipping Charges - _TC",