fix(e-invoice): do not validate gstin for exports (#24561)

diff --git a/erpnext/regional/india/e_invoice/utils.py b/erpnext/regional/india/e_invoice/utils.py
index 876016f..4cf0b18 100644
--- a/erpnext/regional/india/e_invoice/utils.py
+++ b/erpnext/regional/india/e_invoice/utils.py
@@ -304,7 +304,7 @@
 			_('GSTIN is mandatory to fetch company GSTIN details. Please enter GSTIN in selected company address.'),
 			title=_('Missing Fields')
 		)
-	if not frappe.db.get_value('Address', invoice.customer_address, 'gstin'):
+	if invoice.gst_category != 'Overseas' and not frappe.db.get_value('Address', invoice.customer_address, 'gstin'):
 		frappe.throw(
 			_('GSTIN is mandatory to fetch customer GSTIN details. Please enter GSTIN in selected customer address.'),
 			title=_('Missing Fields')