fix: incorrect customer outstanding amount (#38475)

* fix: incorrect customer outstanding amount

* chore: resolve linting error

Co-authored-by: Raffael Meyer <14891507+barredterra@users.noreply.github.com>

---------

Co-authored-by: Raffael Meyer <14891507+barredterra@users.noreply.github.com>
(cherry picked from commit 3df1d75bdd)

erpnext/selling/doctype/customer/customer.py

@@ -582,7 +582,8 @@ def get_customer_outstanding(
 		"""
 		select sum(debit) - sum(credit)
 		from `tabGL Entry` where party_type = 'Customer'
-		and party = %s and company=%s {0}""".format(
+		and is_cancelled = 0 and party = %s
+		and company=%s {0}""".format(
 			cond
 		),
 		(customer, company),